R&S/R&S AMIQ Series Operation R&S
User Manual: R&S/R&S AMIQ Series Operation
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Test and Measurement Division Operating Manual I/Q Modulation Generator AMIQ 1110.2003.02/03/04 valid as of firmware version 4.00 Printed in the Federal Republic of Germany 1110.3339.12-08- 1 AMIQ Tabbed Divider Overview Tabbed Divider Overview Contents Data Sheet Safety Instructions Certificate of Quality EU Certificate of Conformity List of R&S Representatives Contents of Manuals for I/Q Modulation Generator AMIQ Tabbed Divider 1 Chapter 1: Putting into Operation 2 Chapter 2: Getting Started 3 Chapter 3: Operation 4 Chapter 4: Functional Description 5 Chapter 5: Remote Control – Basics 6 Chapter 6: Remote Control – Commands 7 Chapter 7: Examples 8 Chapter 8: Maintenance 9 Chapter 9: Error Messages 10 1110.3339.12 Index RE E-1 AMIQ Contents Contents 1 Putting into Operation......................................................................................... 1.1 Introduction ...................................................................................................................................... 1.1 Front and Rear View ........................................................................................................................ 1.2 Putting into Operation ..................................................................................................................... 1.2 Unpacking................................................................................................................................ 1.2 Setting Up ................................................................................................................................ 1.3 Rackmounting.......................................................................................................................... 1.3 Connection to AC Supply......................................................................................................... 1.4 Power Fuses............................................................................................................................ 1.4 Power Up / Switch-on Test ...................................................................................................... 1.4 Instrument Switch-off............................................................................................................... 1.6 EMC Shielding Measures ........................................................................................................ 1.6 Connection to Test Setup ............................................................................................................... 1.7 Connecting the Controller ........................................................................................................ 1.7 Software for AMIQ Control ...................................................................................................... 1.8 Signal Inputs and Outputs ....................................................................................................... 1.8 Connecting BER Test Signals ................................................................................................. 1.9 Connecting other Facilities .................................................................................................... 1.10 Installation of Options................................................................................................................... 1.11 Option AMIQ-B1, BER Test................................................................................................... 1.11 Option AMIQ-B2, Differential I/Q Outputs.............................................................................. 1.11 Option AMIQ-B3, Digital I/Q Output ............................................................................................. 1.12 Option AMIQB19, I/Q Rear-Panel Connection ...................................................................... 1.12 Option AMIQK11, IS-95 CDMA ............................................................................................. 1.12 Option AMIQK12, CDMA 2000 .............................................................................................. 1.12 Option AMIQK13, Digital Standard W-CDMA TTD Mode (3GPP) ........................................ 1.12 Option AMIQK14, Digital Standard TD-SCDMA .................................................................... 1.12 Option AMIQK15, OFDM Signal Generation ......................................................................... 1.12 Option AMIQK16, Digital Standard 802.11b Wireless LAN ................................................... 1.13 Initial Installation or Update of AMIQ Software........................................................................... 1.13 2 Getting Started..................................................................................................... 2.1 Control via Serial Interface ...................................................................................................... 2.1 Control via IEC/IEEE-Bus Interface ......................................................................................... 2.2 Control via Floppy.................................................................................................................... 2.3 Switchover between Remote-Control Interfaces ..................................................................... 2.3 3 Operation ............................................................................................................. 3.1 Control Elements ..................................................................................................................... 3.1 Indicating Elements (LEDs) ..................................................................................................... 3.1 Calculation of I/Q Modulation Signals...................................................................................... 3.2 Control via WinIQSIM.................................................................................................... 3.2 Control via Vector Signal Generator SMIQ ................................................................... 3.2 1110.3339.12 3 E-7 Contents AMIQ 4 Functional Description........................................................................................ 4.1 Uses ................................................................................................................................................. 4.1 Stress Signals for I/Q Signals .................................................................................................. 4.1 Special Characteristics for Use of AMIQ as I/Q Modulation Source ...................................... 4.2 Basic Operating Modes................................................................................................................... 4.3 Signal Outputs ................................................................................................................................. 4.4 Marker Outputs........................................................................................................................ 4.4 Clock Output and Input.................................................................................................. 4.5 Triggering ......................................................................................................................................... 4.5 I/Q Signal Adjustments.................................................................................................................... 4.7 Adjusting the Level .................................................................................................................. 4.7 Adjusting the Offset ................................................................................................................. 4.7 Adjusting the Delay.................................................................................................................. 4.7 AMIQ – Block Diagram ............................................................................................................ 4.8 Measurement of Bit Error Rate....................................................................................................... 4.9 Connector ................................................................................................................................ 4.9 Signal Path and Waveform.................................................................................................... 4.10 Test Method........................................................................................................................... 4.11 PRBS Polynomials................................................................................................................. 4.13 Measurement Result, Accuracy, Measurement Time ........................................................... 4.13 Possible Problems with BER Measurement and Related Solutions...................................... 4.14 Further Hints and Tricks ........................................................................................................ 4.15 Installation of Option AMIQ-B1, BER Measurement.............................................................. 4.16 Avoid Reflections in the BER Measurement.......................................................................... 4.17 Application Example for Option Differential Outputs ................................................................ 4.18 AMIQ Model 03 / 04 ........................................................................................................................ 4.20 Digital I/Q Output Option AMIQ-B3 .............................................................................................. 4.21 Operation of Digital I/Q Output Option (AMIQ-B3) using WinIQSIM ..................................... 4.22 Pin Allocation of Digital I/Q Outputs....................................................................................... 4.23 Brief Specifications ................................................................................................................ 4.23 Technical Details ................................................................................................................... 4.24 IEEE 488 Commands ............................................................................................................ 4.25 External Clock ................................................................................................................................ 4.26 Brief Description .................................................................................................................... 4.26 Operation ............................................................................................................................... 4.27 IEC/IEEE-bus command........................................................................................................ 4.27 Multisegment Waveform ............................................................................................................... 4.28 Application and structure ....................................................................................................... 4.28 IEC/IEEE bus commands ...................................................................................................... 4.29 1110.3339.12 4 E-6 AMIQ Contents 5 Remote Control - Basics..................................................................................... 5.1 Short Introduction............................................................................................................................ 5.1 Messages.......................................................................................................................................... 5.1 Interface Messages ................................................................................................................. 5.2 Device Messages (Commands and Device Responses) ........................................................ 5.2 Structure and Syntax of the Device Messages ............................................................................. 5.3 SCPI Introduction..................................................................................................................... 5.3 Structure of a Command ......................................................................................................... 5.3 Structure of a Command Line.................................................................................................. 5.5 Responses to Queries ............................................................................................................. 5.6 Parameters .............................................................................................................................. 5.6 Overview of Syntax Elements.................................................................................................. 5.8 Instrument Model and Command Processing .............................................................................. 5.9 Input Unit ................................................................................................................................. 5.9 Command Recognition .......................................................................................................... 5.10 Data Set and Instrument Hardware ....................................................................................... 5.10 Status Reporting System ....................................................................................................... 5.10 Output Unit............................................................................................................................. 5.11 Command Sequence and Command Synchronization.......................................................... 5.11 Status Reporting System .............................................................................................................. 5.12 Structure of an SCPI Status Register .................................................................................... 5.12 Overview of Status Registers ................................................................................................ 5.14 Description of the Status Registers ....................................................................................... 5.15 Status Byte (STB) and Service Request Enable Register (SRE) ................................ 5.15 IST Flag and Parallel Poll Enable Register (PPE)....................................................... 5.16 Event Status Register (ESR) and Event Status Enable Register (ESE) ..................... 5.16 STATus:OPERation Register ...................................................................................... 5.17 STATus:QUEStionable Register ................................................................................. 5.17 Application of the Status Reporting System .......................................................................... 5.18 Service Request, Making Use of the Hierarchy Structure ........................................... 5.18 Serial Poll .................................................................................................................... 5.19 Parallel Poll.................................................................................................................. 5.19 Query by Means of Commands................................................................................... 5.19 Error Queue Query...................................................................................................... 5.19 Reset Values of the Status Reporting Systems..................................................................... 5.20 Hardware Interfaces....................................................................................................................... 5.21 IEC/IEEE Bus Interface......................................................................................................... 5.21 Characteristics of the Interface.............................................................................................. 5.21 Bus Lines ............................................................................................................................... 5.21 Interface Functions ................................................................................................................ 5.22 Interface Messages ............................................................................................................... 5.23 RS-232-C Interface ......................................................................................................................... 5.24 Interface characteristics......................................................................................................... 5.24 Signal lines ............................................................................................................................ 5.24 Transmission parameters...................................................................................................... 5.25 Interface functions ................................................................................................................. 5.25 Handshake ............................................................................................................................ 5.26 1110.3339.12 5 E-7 Contents AMIQ 6 Remote Control – Commands and Data Formats ............................................. 6.1 Notation ................................................................................................................................... 6.1 Common Commands .............................................................................................................. 6.3 BERT – Bit Error Rate Tests ................................................................................................... 6.8 CALibration – Adjustment and Calibration............................................................................. 6.13 DIAGnostic – Hardware Diagnosis ........................................................................................ 6.17 MARKer – Marker Management............................................................................................ 6.20 MEMory/MMEMory – Waveform Management ..................................................................... 6.22 OUTPut – Hardware Settings ................................................................................................ 6.35 PROGram – Program Sequence Control .............................................................................. 6.41 SOURce – Hardware Settings ............................................................................................... 6.42 STATus – Status Reporting................................................................................................... 6.47 SYSTem – Various Settings .................................................................................................. 6.50 ARM/TRIGger/ABORt – Triggering, Sequence Control......................................................... 6.54 Waveform File Format........................................................................................................... 6.57 Creating a Waveform File „Manually“.......................................................................... 6.64 Converting a Waveform File with the Application Software AMIQ-K2......................... 6.66 Example of combining waveform files:........................................................................ 6.68 List of Commands.................................................................................................................. 6.70 Remote-control commands ......................................................................................... 6.70 Tags for Determining the Waveform File Formats...................................................... 6.73 7 Examples.............................................................................................................. 7.1 Program examples for Remote Control......................................................................................... 7.1 Including IEC/IEEE-Bus Library for QuickBasic ...................................................................... 7.1 Initialization and Default Status ............................................................................................... 7.2 Initializing the Controller ................................................................................................ 7.2 Functions for Receiving and Sending Data and Commands ........................................ 7.2 Initializing the Instrument............................................................................................... 7.2 Sending Device Setting Commands........................................................................................ 7.3 Switchover to Manual Control.................................................................................................. 7.3 Executing Batch Programs ...................................................................................................... 7.4 Reading out Device Settings ................................................................................................... 7.4 Command Synchronization...................................................................................................... 7.5 Service Request ...................................................................................................................... 7.6 Selftest with Progress Indication.............................................................................................. 7.7 Waveform Descriptions................................................................................................................. 7.10 GSM Signals (GMSK)............................................................................................................ 7.10 GSM continuous, PRBS 9 data ................................................................................... 7.10 GSM Normal Burst ...................................................................................................... 7.10 GSM Normal Burst, BERT PRBS 9 data..................................................................... 7.11 EDGE Signals (8PSK) ........................................................................................................... 7.12 EDGE Normal Burst .................................................................................................... 7.12 EDGE Normal Burst, BERT PRBS 9 data................................................................... 7.12 GSM/EDGE (GMSK/8PSK) alternating Bursts............................................................ 7.13 NADC Signals........................................................................................................................ 7.14 NADC continuous, PRBS 9 data ................................................................................. 7.14 NADC Downlink Burst ................................................................................................. 7.14 NADC Downlink Burst, BERT PRBS 9 data................................................................ 7.15 1110.3339.12 6 E-6 AMIQ Contents DECT Signals ........................................................................................................................ 7.16 DECT continuous, PRBS 9 data ................................................................................. 7.16 Bluetooth Signals................................................................................................................... 7.17 Bluetooth continuous, PRBS 9 data ............................................................................ 7.17 Bluetooth continuous, PRBS 15 data .......................................................................... 7.17 3GPP (FDD) W-CDMA Signals ............................................................................................. 7.18 Testmodel 1, 16 Channels .......................................................................................... 7.18 Testmodel 1, 32 Channels .......................................................................................... 7.18 Testmodel 1, 64 Channels .......................................................................................... 7.19 Testmodel 2................................................................................................................. 7.19 Testmodel 3, 16 Channels .......................................................................................... 7.20 Testmodel 3, 32 Channels .......................................................................................... 7.20 Testmodel 4................................................................................................................. 7.21 Uplink DPCH Mode, 1 DPCH (60 ksps) ...................................................................... 7.21 Uplink DPCH Mode, 1 DPCH (960 ksps) .................................................................... 7.22 Uplink DPCH Mode, 6 DPCH (960 ksps) .................................................................... 7.22 Uplink PRACH only Mode ........................................................................................... 7.23 Uplink PCPCH only Mode ........................................................................................... 7.23 IS95 CDMA Signals ............................................................................................................... 7.24 Pilot Signal................................................................................................................... 7.24 Pilot Signal (with ACPR filter) ...................................................................................... 7.24 9 Channels .................................................................................................................. 7.25 9 Channels (with ACPR filter)...................................................................................... 7.25 9 Channels, worst case Crest ..................................................................................... 7.26 9 Channels, worst case Crest (with ACPR filter)......................................................... 7.26 64 Channels ................................................................................................................ 7.27 Uplink Signal (1 Access, 1 Traffic Channel)................................................................ 7.27 Multicarrier Signals ................................................................................................................ 7.28 15 CW Carriers, maximum Crest ................................................................................ 7.28 15 CW Carriers, minimum Crest ................................................................................. 7.28 8 GSM carriers ............................................................................................................ 7.29 8 EDGE carriers .......................................................................................................... 7.29 5 NADC carriers .......................................................................................................... 7.29 Multicarrier Mixed Signals...................................................................................................... 7.30 3 WCDMA 3GPP carriers, 5 MHz spacing.................................................................. 7.30 3 WCDMA 3GPP carriers, 10 MHz spacing................................................................ 7.30 1 WCDMA 3GPP carrier + 1 EDGE carrier ................................................................. 7.31 1 CDMA IS95 carrier + 1 NADC carrier....................................................................... 7.31 8 Maintenance......................................................................................................... 8.1 Mechanical and Electrical Maintenance .................................................................................. 8.1 Storing and Packing................................................................................................................. 8.1 9 Error Messages ................................................................................................... 9.1 Troubleshooting .............................................................................................................................. 9.1 List of Error Messages .................................................................................................................... 9.2 SCPI Standard Messages ....................................................................................................... 9.2 No error ......................................................................................................................... 9.2 Operation complete ....................................................................................................... 9.2 Query error - error upon data request ........................................................................... 9.3 Device-specific error...................................................................................................... 9.3 Execution error .............................................................................................................. 9.4 Command error ............................................................................................................. 9.5 AMIQ-Specific Messages ........................................................................................................ 9.7 1110.3339.12 7 E-7 ContentsFigures AMIQ Figures Fig. 1-1 Fig. 1-2 Fig. 1-3 Fig. 4-1 Fig. 4-2 Fig. 4-3 Fig. 4-4 Fig. 4-5 Fig. 4-6 Fig. 4-7 Fig. 4-8 Fig. 4-9 Fig. 5-1 Fig. 5-2 Fig. 5-3 Fig. 5-4 Fig. 5-5 Fig. 5-6 Fig. 5-7 AMIQ used in a test setup .................................................................................................. 1.1 AMIQ Front view................................................................................................................. 1.2 AMIQ rear view................................................................................................................... 1.3 Simplified block diagram of AMIQ ...................................................................................... 4.8 PRBS Polynomials............................................................................................................ 4.13 Avoid reflections in the BER measurement...................................................................... 4.17 Application block diagram of option AMIQ-B2.................................................................. 4.18 Pin allocation of digital I/Q outputs ................................................................................... 4.23 Technical implementation of digital I/Q outputs................................................................ 4.24 Integration of the AMIQ into a system with system clock ................................................. 4.26 Feeding a DUT with a spectrally pure external clock ....................................................... 4.26 Generation of an MWV from partial traces....................................................................... 4.29 Example for the tree structure of the SCPI command systems: The SYSTem system...... 5.4 Instrument model in the case of remote control by means of the IEC bus......................... 5.9 The status register model................................................................................................. 5.12 The Status registers ......................................................................................................... 5.14 Pin Assigment of the IEC-bus interface............................................................................ 5.21 Pin assigment of the RS-232-C interface ......................................................................... 5.24 Null-modem connection scheme ...................................................................................... 5.26 Tables Table 4-1 Table 4-2 Table 5-1 Table 5-2 Table 5-3 Table 5-4 Table 5-5 Table5-6 Table 5-7 Table 5-8 Table 5-9 Table 5-10 Table 6-1 Table 6-2 Table 6-3 Table 6-4 Table 6-5 Table 6-6 Table 6-7 Table 6-8 Table 6-9 Table 6-10 Table 6-11 Table 6-12 Table 6-13 Table 6-14 Table 9-1 1110.3339.12 Specifications of option AMIQ-B3 .................................................................................. 4.23 IEEE 488 commands for option AMIQ-B3 ..................................................................... 4.25 Synchronization with *OPC, *OPC? and *WAI .............................................................. 5.11 Meaning of the bits used in the status byte.................................................................... 5.15 Meaning of the bits used in the event status register..................................................... 5.16 Meaning of the bits used in the STATus:OPERation register ........................................ 5.17 Meaning of the bits used in the STATus:QUEStionable register ................................... 5.17 Resetting instrument functions ...................................................................................... 5.20 Interface functions.......................................................................................................... 5.22 Universal Commands .................................................................................................... 5.23 Addressed Commands .................................................................................................. 5.23 Control strings or control characters of the RS-232-C interface .................................... 5.25 Common commands ....................................................................................................... 6.3 BERT – Bit error rate tests............................................................................................... 6.9 CALibration – Adjustment and calibration...................................................................... 6.13 DIAGnostic – Hardware diagnosis ................................................................................. 6.17 MARKer – Marker management .................................................................................... 6.20 MEMory – Waveform management............................................................................... 6.22 MMEMory – Waveform management............................................................................ 6.23 OUTPut – Hardware settings ......................................................................................... 6.35 PROGram – Program sequence.................................................................................... 6.41 SOURce – Hardware settings........................................................................................ 6.42 Status reporting.............................................................................................................. 6.47 System settings.............................................................................................................. 6.50 ARM/TRIGger /ABORt – Triggering, sequence control................................................. 6.54 List of all remote-control commands.............................................................................. 6.70 Error symptoms................................................................................................................ 9.1 8 E-7 Safety Instructions This unit has been designed and tested in accordance with the EC Certificate of Conformity and has left the manufacturer’s plant in a condition fully complying with safety standards. To maintain this condition and to ensure safe operation, the user must observe all instructions and warnings given in this operating manual. Safety-related symbols used on equipment and documentation from R&S: Observe operating instructions Weight indication for units >18 kg PE terminal Ground terminal 1. The unit may be used only in the operating conditions and positions specified by the manufacturer. Unless otherwise agreed, the following applies to R&S products: IP degree of protection 2X, Pollution severity 2, overvoltage category 2, altitude max. 2000 m. The unit may be operated only from supply networks fused with max. 16 A. 2. For measurements in circuits with voltages Vrms > 30 V, suitable measures should be taken to avoid any hazards. (using, for example, appropriate measuring equipment, fusing, current limiting, electrical separation, insulation). 3. If the unit is to be permanently wired, the PE terminal of the unit must first be connected to the PE conductor on site before any other connections are made. Installation and cabling of the unit to be performed only by qualified technical personnel. 4. For permanently installed units without built-in fuses, circuit breakers or similar protective devices, the supply circuit must be fused such as to provide suitable protection for the users and equipment. 5. Prior to switching on the unit, it must be ensured that the nominal voltage set on the unit matches the nominal voltage of the AC supply network. If a different voltage is to be set, the power fuse of the unit may have to be changed accordingly. 6. Units of protection class I with disconnectible AC supply cable and appliance connector may be operated only from a power socket with earthing contact and with the PE conductor connected. 095.1000 Sheet 17 Danger! Shock hazard Warning! Hot surfaces Ground Attention! Electrostatic sensitive devices require special care 7. It is not permissible to interrupt the PE conductor intentionally, neither in the incoming cable nor on the unit itself as this may cause the unit to become electrically hazardous. Any extension lines or multiple socket outlets used must be checked for compliance with relevant safety standards at regular intervals. 8. If the unit has no power switch for disconnection from the AC supply, the plug of the connecting cable is regarded as the disconnecting device. In such cases it must be ensured that the power plug is easily reachable and accessible at all times (length of connecting cable approx. 2 m). Functional or electronic switches are not suitable for providing disconnection from the AC supply. If units without power switches are integrated in racks or systems, a disconnecting device must be provided at system level. 9. Applicable local or national safety regulations and rules for the prevention of accidents must be observed in all work performed. Prior to performing any work on the unit or opening the unit, the latter must be disconnected from the supply network. Any adjustments, replacements of parts, maintenance or repair may be carried out only by authorized R&S technical personnel. Only original parts may be used for replacing parts relevant to safety (eg power switches, power transformers, fuses). A safety test must be performed after each replacement of parts relevant to safety. (visual inspection, PE conductor test, insulationresistance, leakage-current measurement, functional test). continued overleaf Safety Instructions 10. Ensure that the connections with information technology equipment comply with IEC950 / EN60950. 11. Lithium batteries must not be exposed to high temperatures or fire. Keep batteries away from children. If the battery is replaced improperly, there is danger of explosion. Only replace the battery by R&S type (see spare part list). Lithium batteries are suitable for environmentally-friendly disposal or specialized recycling. Dispose them into appropriate containers, only. Do not short-circuit the battery. 12. Equipment returned or sent in for repair must be packed in the original packing or in packing with electrostatic and mechanical protection. 095.1000 Sheet 18 13. Electrostatics via the connectors may dama- ge the equipment. For the safe handling and operation of the equipment, appropriate measures against electrostatics should be implemented. 14. The outside of the instrument is suitably cleaned using a soft, line-free dustcloth. Never use solvents such as thinners, acetone and similar things, as they may damage the front panel labeling or plastic parts. 15. Any additional safety instructions given in this manual are also to be observed. EC Certificate of Conformity Certificate No.: 98034 This is to certify that: Equipment type Order No. Designation AMIQ 1110.2003.02/.03/.04 I/Q Modulation Generator AMIQ-B2 AMIQ-B3 AMIQB19 1110.3700.02/.03 1122.2103.02 1110.3400.02 Differential I/Q Outputs Digital I/Q Output I/Q Rear Panel Connection complies with the provisions of the Directive of the Council of the European Union on the approximation of the laws of the Member States - relating to electrical equipment for use within defined voltage limits (73/23/EEC revised by 93/68/EEC) - relating to electromagnetic compatibility (89/336/EEC revised by 91/263/EEC, 92/31/EEC, 93/68/EEC) Conformity is proven by compliance with the following standards: EN61010-1 : 1993 + A2 : 1995 EN50081-1 : 1992 EN50082-2 : 1995 Affixing the EC conformity mark as from 1998 ROHDE & SCHWARZ GmbH & Co. KG Mühldorfstr. 15, D-81671 München Munich, 1999-09-17 1110.2003.02 Central Quality Management FS-QZ / Becker CE E-1 AMIQ Manuals Contents of Manuals for I/Q Modulation Generator AMIQ Operating Manual The operating manual consisting of a data sheet and 10 chapters contains comprehensive information on characteristics, putting into operation, operation and remote control of AMIQ: The data sheet informs about guaranteed specifications and characteristics. Chapter 1 describes the operating principle of AMIQ, control elements and connectors on the front and rear panel as well as all procedures required for putting the instrument into operation and integration into a test system. Chapter 2 details instrument control via the remote interfaces with the aid of program examples. Chapter 3 presents control and display elements. Chapter 4 describes key operating modes and special characteristics of AMIQ with reference to possible applications. Chapter 5 describes programming of AMIQ, command processing, status reporting system and characteristics of hardware interfaces. Chapter 6 describes the remote-control commands defined for the instrument. At the end of the chapter an alphabetical list of commands is given. Chapter 7 contains program examples for a number of typical applications of AMIQ. Chapter 8 describes preventive maintenance. Chapter 9 gives hints on troubleshooting and contains a list of error messages. Chapter 10 contains an index for the operating manual. Service Manual The service manual informs on how to check compliance with rated specifications, on instrument function, repair, troubleshooting and fault elimination. It contains all information required for the maintenance of AMIQ by exchanging modules. The service manual also contains the circuit documentation for the module "IQ Analog/Digital Unit". 1110.3339.12 0.1 E-2 AMIQ Introduction 1 Putting into Operation Introduction Task AMIQ is a modulation source for complex baseband signals of state-of-the-art telecommunication networks. Two synchronous outputs, which are matched to each other, and a large memory together with wide analog bandwidth make AMIQ suitable for universal use. AMIQ has been designed to generate I and Q signals in the baseband for present and future types of modulation. "I" stands for the in-phase component, "Q" for the quadrature component. Operating principle The data to be output by AMIQ are normally calculated by an external workstation (eg PC). To control this calculation, Rohde & Schwarz offers two programs: WINIQSIM and AMIQ Control, a software for R&S vector signal generator SMIQ (see Section "Software for AMIQ Control on page 1.8"). The desired information data stream (eg a piece of speech) is generated and a modulation mode selected. Then various interference and distortions (so-called impairments) are superimposed to this (ideal) baseband signal. Thus a long sequence of sample values is obtained, which are loaded into AMIQ (via floppy, IEC/IEEE bus or RS-232 interface). The sequence in the AMIQ memory is then output as analog I and Q signals with the aid of fast and accurate D/A converters. The outputs are (normally) connected to the modulation inputs of an I/Q modulator (eg SMIQ), which modulates the baseband signal onto the desired RF (Fig. 1-1). Transmission error The RF signal is transmitted via the antenna to the receiver where it is converted back into information data. On the transmission link, errors may be caused in the information data stream by coding, impairments and decoding. These errors can be detected with the aid of option AMIQ-B1 (BER measurement) and evaluated. AMIQ I/Q MODU LATION GENER ATOR . AMIQ ON CONTROL I RUNNING Bit error rate test (optional) 1110 .20 03. 02 Q M A DE IN G E RM A NY Device under test (DUT) SMIQ SMIQ ï ð RF Fig. 1-1 Test setup 1110.3339.12 AMIQ used in a test setup The four additional marker outputs and a trigger input simplify integration in a test setup. The user-selectable positions of the marker switch points permit external, variable amplifiers (eg for power ramping) or signalling facilities to be controlled. 1.1 E-6 Front and Rear View AMIQ Front and Rear View 3,5''-disk drive Power switch I In-phase component Q Quadrature component Chapter 1 "Introduction" preset in as long as Instrument is on . I/Q MODULATION GENERATOR . AMIQ ON CONTROL RUNNING I Refer to "Installation of Options" in chapter 1 when exchanging data and instrument software 1110.2003. 03 I Q Q DIGITAL OUTPUT M A D E IN G E R M A N Y 3 LEDs indicating the instrument status ON CONTROL RUNNING Additional outputs T and Q with option Differential I/Q Outputs installed Option Digital I/Q Output AMIQ-B3 AMIQ ready for operation Remote control active Waveform in output memory in triggered Chapter 1 . "Power up / Switch-onTest" Fig. 1-2 AMIQ Front view Putting into Operation Caution! The following instructions should be strictly observed, in particular when putting the instrument into operation for the first time, to avoid damage to the instrument and hazards to persons. Unpacking After unpacking the instrument, check for completeness according to the delivery note and the accessory lists for the individual items. Remove the two protective covers from the front and rear of the AMIQ and carefully check the instrument for any damage. In case of any damage you should immediately inform the responsible transport agent and keep all packing material not to forfeit your claims. Remove protective covers The original packing should also be used for any later transport or shipment of AMIQ. You should keep at least the two protective covers for the front and rear of the instrument. 1110.3339.12 1.2 E-6 AMIQ Putting into Operation Power connector with 2 fuses (F) "Connection to AC Supply" in chapter 1 RS-232 interface "Connecting the Controller" in chapter 1 Connector for servicing and extensions "Connecting other Facilities" in chapter 1 100...120 / 200...240 V 50...60 Hz 150 VA X 10 IEC/IEEE-bus interface "Connection the Controller" in chapter 1 625 IEEE 488 SCPI F 1 / F 2: IEC 127 - T 2.5 H / 250 V AUTO POWER SELECTION REF REF CLK Reference frequency Input / Output Q FILT Q 1 MARK 2 Q filter, input and output Clock input/output 3 MARK I 4 FILT I TRIG BER I filter, input and output BER input "Connecting BER Test Signals" in chapter 1 Trigger input Air vents 4marker outputs With option "Rear IQ outputs (AMIQ-B19) installed, MARK 3 willl become Q and MARK 4 I. "Signal Inputs and Outputs" in chapter 1 Fig. 1-3 AMIQ rear view Setting Up Permissible setup positions for AMIQ: • Flat. • Upright standing on its rear. In this case an angular AC supply connector should be used. Note: To ensure problem-free operation of the instrument the following should be observed: • Do not obstruct air vents at the rear and sides. • Observe the permissible ambient temperature specified in the data sheet. • Avoid condensation. Allow instrument with condensation to dry before switching on. Rackmounting Adapter ZZA-211 (Order No. 1096.3260.00) allows the AMIQ to be mounted in 19" racks. Rackmounting is described in the installation instructions of the rack adapter. For rackmounting it is recommended to fit the option AMIQB19 (I/Q Rear-Panel Connection) (Order No. 1110.3400.02), which changes I and Q connectors from the front to the rear. Note: To ensure problem-free operation of the instrument the following should be observed: • Provide for sufficient air flow in the rack. • Make sure that there is sufficient space between air vents and rack. 1110.3339.12 1.3 E-6 Putting into Operation AMIQ Connection to AC Supply Caution! Allow instrument with condensation to dry before switching on. Observe permissible ambient temperatures -10°C to +45°C. Do not cover up air vents. AMIQ may be connected to a single-phase AC supply with a rated voltage from 100 V to 240 V and rated frequency from 50 Hz to 60 Hz. Note: AMIQ automatically sets itself to the local AC supply voltage. There is no need for external switchover or exchanging fuses. ← AC supply connector ← Power fuses Use the power cord supplied with the AMIQ for connection to the AC supply. Since the AMIQ is designed in line with protection class I requirements to EN61010 it may only be connected to an earthingcontact type connector. As soon as the connection has been established, AMIQ outputs a beep and the ON LED lights with slightly reduced brightness. After the start-up is completed, the ON LED is fully on. Power Fuses AMIQ is fully fused by two fuses IEC127-T4.0H/250 V. The fuses are accommodated in the pull-out fuse holder below the power connector. Before replacing the fuses, disconnect the power cord from the AMIQ. Use a screwdriver to lift the fuse holder below the power connector and pull it out. Use only fuses of the above type. Power Up / Switch-on Test Ø Press switch-on key on the AMIQ front panel. Note: No floppy should be in the drive when AMIQ is switched on. If this happens nonetheless, one of the actions stored on the floppy may be executed (see sections "New installation of AMIQ software" and "Changing the IEC/IEEE-bus address in this chapter). Start-up procedure After power-up the system is started, the controller short test is performed and the operating system DOS and the remote-control software are loaded from the integrated hard disk. During this time the ON LED lights with reduced intensity. Test of controller hardware First the switch-on test for the integrated controller is performed. Since at this stage the LEDs are not driven, no information can be obtained on the device status. If a fault occurs, AMIQ outputs a sequence of beeps, the meaning of which can be seen in the enclosed main board manual. If a fault occurs, the switch-on procedure is normally aborted. 1110.3339.12 1.4 E-6 AMIQ Short test of functional hardware Putting into Operation The AMIQ hardware is then set to operating state and tested. Any error is signalled by two short successive beeps provided the built-in loudspeaker was not switched off with the IEC/IEEE-bus command :SYST:BEEP:STAT OFF. At the end of the selftest a single beep is output. After this the instrument is ready for operation. Further information on error can be obtained by a repeated readout of the error queue using IEC/IEEE-bus queries :SYST:ERR?. Even if an error occurs, the switch-on procedure is in most cases continued so that the error queue can be read out. The instrument may not be fully functional however. LEDs after the short test If an error is detected in the short test, the ON LED flashes. With the short test completed successfully, the last active setup is automatically loaded from the hard disk and the instrument is set to the operating status before switch-off. The currently selected waveform is loaded together with this complete setup. For a curve with 4.000.000 samples and with AMIQ 03, this may take up approx. 20 seconds. With AMIQ 04 and its quadrupled memory capacity, the loading time increases to approx. 80 s. If no further errors occurred, the ON and the CONTROL LEDs briefly light. Afterwards, the ON and RUN LEDs come fully on. Error messages If an error is detected the error message is entered in plain text into the error queue of AMIQ and ON LED flashes. This is why after restart the AMIQ control program in the host computer should read out the error queue by means of the command SYST:ERR? until it is empty, i.e., until the entry 0,"No Error" is read. Depending on the error detected, AMIQ will usually respond to commands transmitted via IEEE-bus or RS-232 interface but may not be fully functioning. The ON LED lights steadily at full brightness. Note If ON LED flash fast, it is only a hint that AMIQ does not generate any curve at the moment. It appears whenever a curve was stored directly to the AMIQ’s SDRAM to save time before switching off AMIQ by means of the MEM:DATA RAM,command (e.g. with WinIQSIM via the settings Transmission, Force internal, Destination AMIQ-RAM). This can be suppressed by loading curves via a waveform file using the command MMEM:LOAD RAM, 'filename.WV'; such a curve is available immediately after switching on the instrument. Ø If AMIQ does not start as described above, check the AC supply connection and, if required, replace the two power fuses (see section "Power fuses" in this chapter). Ø A complete selftest of AMIQ’s hardware components can be started with the common command *TST?. Furthermore, the command DIAG:SELF:SDRAM? can be used to test the whole SDRAM of AMIQ in detail, see Sections „Common Commands“ and „DIAGnostic – Hardware Diagnosis“ in Chapter 6. 1110.3339.12 1.5 E-6 Putting into Operation AMIQ Instrument Switch-off Ø Wait until the hard disk or the floppy disk drive are no longer accessed Ø Remove floppy from the disk drive Ø Press power switch on the front panel. All instrument settings are retained. EMC Shielding Measures To avoid electromagnetic interference, the instrument must always be closed when in operation. Use only appropriate, shielded signalling lines and control cables. Particularly the line connected to the clock output should be double-shielded and terminated. 1110.3339.12 1.6 E-6 AMIQ Connection to Test Setup Connection to Test Setup Connecting the Controller AMIQ has no user interface of its own. An external controller is therefore required for operating AMIQ which can be performed in two ways: Connection via IEC/IEEE bus AMIQ is simply connected to the IEC/IEEE bus. Upon delivery the bus address is 6. If the bus address has been changed, e.g. by a previous control command, or if the bus address has to be changed, proceed as described in section "Changing the IEC/IEEE-bus address" on page 1.7. Connection via the serial interface AMIQ is connected to the serial interface of a PC by means of a null modem cable. Connect the cable to the 9-contact sub-D connector of the AMIQ labeled RS232. Use the COM1 or COM2 connector of the PC which may be a 25-contact or 9-contact connector. Suitable adapters may have to be used. Serial interface The serial interface is configured for 9600 Baud, 8 data bits, no parity. When the WinIQSIM software is used, which is recommended by R&S, the interface of the PC is automatically configured with the AMIQ settings. However, the interface used has to be set in the menu first. Pin assignment and wiring of the null modem cable are described in section "Handshake" of chapter 5. Changing the IEC/IEEE-bus Address Upon delivery the instrument is set to address 6. If for any reason this address is not available, the setting can be changed as follows: Ø Generate a file on a PC, which contains only the following line: :SYST:COMM:GPIB:ADDR x with x being the desired address. Add an empty line. Ø Copy this file under the name AUTOEXEC.IEC into the main memory of a 3.5" floppy. Ø Insert the floppy in the AMIQ, switch AMIQ off and on again. 1110.3339.12 1.7 E-6 Connection to Test Setup AMIQ Software for AMIQ Control AMIQ can only be remote-controlled. To simplify operation, Rohde & Schwarz offers two different software programs for the control of AMIQ: • WinIQSIM: This software permits calculation of complex I/Q signals, controls the transfer of these signals to the AMIQ via IEEE-bus or RS-232 interface and determines how the signals are output. • AMIQ control software menu for SMIQ: In this case AMIQ is controlled from SMIQ. Control is similar to that of the SMIQ options but I/Q signals cannot be generated. It is possible, however, to load I/Q signals that have been generated on an external PC. Signal Inputs and Outputs Analog I/Q output: I I The loaded waveforms are output at two BNC connectors I and Q on the front panel (four BNC connectors I and I, Q andQ if option Differential Outputs (AMIQ-B2) is fitted). The output is determined by the trigger conditions and depends on the applied trigger signals (see section "Triggering" in chapter 4). If the trace output is not active, an idle-channel signal is output (see section "ARM/TRIGger/ABORt Triggering, Sequence control" in chapter 6). Q Q If option AMIQ-B2 is not fitted the I/Q outputs on the front panel can be taken to the rear with option I/Q Rear-Panel Connection (AMIQB19). This simplifies wiring particularly when the AMIQ is rack-mounted. Note: When the I/Q outputs are taken to the rear, marker outputs 3 and 4 (BNC connectors) are used. This means that marker outputs 3 and 4 are no longer available. Upon delivery and after an *RST, the I and Q outputs are switched off. Use commands OUTPUT:I FIX and OUTPUT:Q FIX to reactivate the channels. Digital I/Q output: Pin 35 Digital Output Pin 1 Pin 68 Option AMIQ-B3, Digital I/Q Output, provides the 16 bit wide data bus for both I and Q channels via a 68-pole SCSI socket at the front panel of the AMIQ. See section "Option "Digital I/Q Output AMIQ-B3" below. Pin 34 TRIG Trigger input (TRIG): Rear BNC connector (female). The output of the stored waveform can be started or enabled with a TTL signal applied to this connector. Trigger condition and polarity are user-selectable. 1 MARK Marker outputs (MARK): Four BNC connectors (female) at the rear. These outputs (TTL level, can be terminated with 50 Ω) are used for the control of further instruments, e.g. an oscilloscope or variable amplifiers (power ramping). (See "Marker outputs" in chapter 4). 1110.3339.12 1.8 E-6 AMIQ Connection to Test Setup FILT I/Q filter (input and output): Here an external passband filter (e.g. for anti-aliasing) can be looped in for the I and Q path instead of the internal filters. The outputs have a nominal impedance of 50 Ω and yield a peak voltage of 0.5 V into 50 Ω when driven at full scale. The filter attenuation in the passband range should be 0 dB. REF Reference clock input (REF): Input for an external 10 MHz reference clock; Vrms = 0.1 V to 2 V, input impedance 50 Ω. REF Reference clock output (REF): Output of 10 MHz reference clock; Vrms = 0.5 V, output impedance 50 Ω. CLK Clock input/output (CLK): Output with the actual clock rate; Vrms = 0.5 V, output impedance 50 Ω. Input for external clock (TTL signal). Caution! Because of the high clock rates at the clock output, a double-screened cable should be used to keep within permissible EMI limits. The line should in all cases be terminated with 50 Ω. Connecting BER Test Signals BER 1110.3339.12 AMIQ comprises a programmable facility for bit error rate (BER) measurements. The required signals have to be applied to the AMIQ via the BER input with TTL level. The signals to be applied depend on the test method used and are described in the manual for option AMIQ-B1 (see section "BER measurement" in chapter 4). 1.9 E-6 Connection to Test Setup AMIQ Connecting other Facilities The connectors labeled LPT/PARALLEL, X10, X11, X12 and X13 are used for servicing or for extensions. Note: 1110.3339.12 In normal operation these connectors must be open. 1.10 E-6 AMIQ Installation of Options Installation of Options The following options are available for AMIQ: BER Measurement Differential I/Q Outputs Digital I/Q Output Rear I/Q Outputs IS-95 CDMA CDMA 2000 Digital Standard W-CDMA TTD Mode (3GPP) TD-SCDMA OFDM Signal Generation Option Digital Standard 802.11b Wireless LAN AMIQ-B1 AMIQ-B2 AMIQ-B3 AMIQB19 AMIQK11 AMIQK12 AMIQK13 AMIQK14 AMIQK15 AMIQK16 1110.3500.02 1110.3700.02 1122.2103.02 1110.3400.02 1122.2003.02 1122.2503.02 1122.2603.02 1122.2703.02 1122.2803.02 1122.2903.02 AMIQ is supplied with the options already fitted. For a subsequent installation of options refer to the fitting instructions supplied with the options or refer to chapter 4 of the Service Manual. Software options AMIQ-B1, AMIQK11, AMIQK12, AMIQK13, AMIQK14, AMIQK15 and AMIQK16 can be activated by the customer. No extra test equipment is needed for the installation. Since the option is activated by means of an enable code, the unit need not be opened. Proceed according to the instructions supplied with the option. Installation of a software option is described at the end of chapter 4 using AMIQ-B1 as an example. The IEC/IEEE bus command to enable a software option is:SYSTem:OPTion , , see chapter 6. In order to fit one of the hardware options AMIQ-B2, AMIQ-B3 or AMIQB19 the casing of the instrument must be opened. This will break the calibration seal so that the calibration is no longer valid. Therefore, these options should be installed by an R&S service representative. Important: The components used in the instrument are sensitive to electrostatic charges and should therefore be handled according to ESD regulations. Option AMIQ-B1, BER Test AMIQ-B1 is a software option which can be installed without opening the instrument. For the installation proceed as described in the instructions supplied with the option. For a description of the BER test refer to chapter 4. Option AMIQ-B2, Differential I/Q Outputs To fit this hardware option the instrument must be opened. Therefore, it must be retrofitted by an authorized service representative. Control of the differential outputs of AMIQ by means of WinIQSIM is supplied starting with version 2.10. For an application example for option Differential Outputs refer to chapter 4. 1110.3339.12 1.11 E-6 Option AMIQ-B3, Digital I/Q Output AMIQ Option AMIQ-B3, Digital I/Q Output Retrofitting the hardware option AMIQ-B3 requires the instrument to be opened. Therefore, it must be done by an authorized service representative. The Digital I/Q Output can be controlled by WinIQSIM version 3.10 and higher. An application example for option Digital I/Q Output is given in chapter 4. Option AMIQB19, I/Q Rear-Panel Connection This option can be fitted only if option Differential Outputs (AMIQ-B2) is not installed. Retrofitting the option requires the instrument to be opened. Therefore, this must be done by an authorized service representative. With option AMIQB19 fitted, marker outputs 3 and 4 are no longer available as these connectors are used as Q and I signal outputs (i.e. the I output is connected to marker output 4, the Q output is connected to marker output 3). Option AMIQK11, IS-95 CDMA Software option for interpreting a waveform file generated according to IS95 by WinIQSIM, version 2.10 or higher. These CDMA signals comply with the IS-95A and J-STD-008 mobile radio standards. Option AMIQK12, CDMA 2000 Software option for interpreting a waveform file generated in WinIQSIM vers. 3.20 according to CDMA 2000. These CDMA signals comply with the IS-2000 mobile radio standard. The 1X and the 3X modes (multi carrier and direct spread) can be simulated at the physical layer. Option AMIQK13, Digital Standard W-CDMA TTD Mode (3GPP) Software option to interpret a waveform file generated in WinIQSIM as of version 3.60. 3GPP TDD (3rd Generation Partnership Project Time Division Duplex) refers to a mobile radio transmission method defined by 3GPP (http://www.3GPP.org). Option AMIQK14, Digital Standard TD-SCDMA Software option to interpret a waveform file generated in WinIQSIM as of version 3.50. TD-SCDMA (time-division synchronous CDMA) designates a mobile-radio transmission method developed by the China Wireless Telecommunication Standard Group (CWTS, http://www.cwts.org). This standard is similar to the 3GPP TDD proposal, but with greater emphasis placed on GSM compatibility and with a chip rate limited to 1.28 Mcps. Option AMIQK15, OFDM Signal Generation Software option for interpreting a waveform file generated in WinIQOFDM with the aid of WinIQSIM Vers. 3.40. Special emphasis is placed on the generation of signals conforming to HIPERLAN/2 or IEEE 802.11a (WinIQOFDM is a PC software that generates OFDM-modulated signals from binary data streams, these signals are then read by WinIQSIM via the DDE interface for further processing). 1110.3339.12 1.12 E-6 AMIQ Initial Installation or Update of AMIQ Software Option AMIQK16, Digital Standard 802.11b Wireless LAN Software option to interpret a waveform file generated in WinIQSIM as of version 3.80. The 802.11b wireless LAN standard is a packet-oriented method for data transmission. The data packets are transmitted and received on the same frequency in time division duplex (TDD), but without a fixed timeslot raster. Initial Installation or Update of AMIQ Software For initial installation of the AMIQ software, a program disk (3.5") is needed. The disk is available from your local sales engineer. It usually contains two files: AMIQxxx.DAT and README.TXT. "xxx" stands for the firmware version number; AMIQ304.DAT means firmware version 3.04, for example. In AMIQxxx.DAT, over 40 files required for the firmware update are packed in compressed form. Insert the disk into the AMIQ floppy disk drive. Then switch the unit off and on again. On switch-on, the unit automatically checks whether an update disk is inserted in the drive. If this is the case, the complete new firmware is loaded from the disk. The download takes approx. 4 minutes and is indicated by a green LED on the floppy disk drive. When the LED goes out, AMIQ is ready for operation. In the event that the firmware is not loaded, a fault may be in the controller which can only be eliminated with the aid of a graphics card (ISA or PCI bus) when the instrument is open and a keyboard is connected (see Service Manual). 1110.3339.12 1.13 E-6 AMIQ Getting Started 2 Getting Started AMIQ can only be remote-controlled. For this purpose a serial interface RS-232, an IEC/IEEE-bus interface and the disk drive are available. This chapter gives a brief introduction to instrument operation via these interfaces. Typical applications, characteristics and operating modes of AMIQ will be described in chapter 4. Control via Serial Interface AMIQ can be connected to the serial interface of a PC via the rear, 9-contact sub-D connector labeled RS 232. Setting example: With the following steps, a 100 kHz sinusoidal signal is obtained at the outputs of AMIQ. ½ Connect instrument and controller by means of the null modem cable (see section "Connecting the Controller" in chapter 1, for pin assignment of null modem cable see "Handshake" in chapter 5). ½ Set the serial interface at the controller to 9600 Baud, no parity, 8 bit, 1 stop bit. Example: To configure the controller interface enter the following command under DOS: mode com : 9600, n, 8, 1 = 1 or 2 depending on connector used. ½ Create the following ASCII file at the controller: (empty line) Sets instrument to remote control Resets the instrument Outputs stored trace (empty line) *RST;*CLS;*WAI *RCL ’SINUS’ ½ Transfer this ASCII file to the instrument via the RS-232 interface. Enter the following command at the controller: copy com : A frequency of 100 kHz is now available at the outputs of the instrument, as this setting is stored under SINUS. Note: Upon delivery and after an *RST the I and Q output are switched off. Use commands OUTPUT:I FIX and OUTPUT:Q FIX to activate the outputs. DOS commands are used for all settings via the serial interface. The use of a terminal emulation program considerably simplifies handling of the serial interface. Since these programs greatly differ, no instructions are given here for their use. Simple terminal programs are for instance available on the Internet, e.g. under http://www.leo.org/archiv/msdos/ or ftp://garbo.uwasa.fi/pc 1110.3339.12 2.1 E-4 Getting Started AMIQ Changing the transmission rate: The instrument is set in the factory to a baud rate of 9600 bps and hardware handshake via RTS and CTS lines. The handshake procedure cannot be changed. When the baud rate is changed or if another rate is required, the rate can be modified as follows: ½ Create a file with the name AUTOEXEC.IEC in the main directory of a 3.5" floppy. Write the following lines into this file: :SYST:COMM:SER:BAUD 9600 and replace 9600 by the baud rate desired (for permissible values see description of command :SYST:COMM:SER:BAUD). ½ Switch off AMIQ, insert the file and start AMIQ. Upon the start the created file is read and the baud-rate setting command executed. Control via IEC/IEEE-Bus Interface The AMIQ can be connected to the IEC/IEEE bus via the rear IEEE 488 connector (see section "Connecting the Controller" in chapter 1). Setting example: With the following control steps a 100 kHz sinusoidal signal is obtained at the outputs of AMIQ. ½ Connect instrument and controller by means of an IEC/IEEE-bus cable. Note: The instrument is set in the factory to the IEC/IEEE-bus address 6. If this address has been changed or is not available (e.g. because it is used by another instrument), the address can be changed as described in section "Changing the IEC/IEEE-bus Address" in chapter 1. ½ Create and start the following program at the controller: CALL CALL CALL CALL IBFIND("DEV1", amiq%) IBPAD(amiq%, 6) IBWRT(amiq%, "*RST;*CLS;*WAI") IBWRT(amiq%, "*RCL ’SINUS’") Opens channel to the instrument Specifies device address at the controller Resets instrument Outputs trace (stored in the instrument upon delivery) A 100 kHz sinewave signal is now available at the outputs of AMIQ. 1110.3339.12 2.2 E-4 AMIQ Getting Started Control via Floppy Purpose In addition to the control capabilities described above, AMIQ can also be controlled via a file in the disk drive. This control function is however not intended for continuous operation but for executing functions (e.g. setting the baud rate or IEC/IEEE-bus address) that are not accessible during normal operation. (see "Control via Serial Interface"). Function On power-up a check is made whether a floppy is in the disk drive and whether this file contains an AUTOEXEC.IEC file. If this is the case the remote-control commands in this file are executed one after the other. The syntax is identical to that used on the IEC/IEEE bus or at the serial interface. Execution of program files The execution of program files can be triggered any time with command PROG:EXEC ’name’ (which has to be transferred via one of the other remotecontrol sources). The called program file is searched for first on the floppy, then on the hard disk. Switchover between Remote-Control Interfaces After power up all remote-control sources (serial interface, IEC/IEEE bus) are active. When the instrument receives a command on one of the two interfaces, the REMOTE LED is switched on and the other interface is deactivated. To be able to use the other interface different procedures can be chosen: • Switch the instrument off and on again • Send command *GTL via the serial interface if the latter is active. • Send the message IBLOC(amiq%) via the IEC/IEEE bus if the latter is active. After the commands in a batch file have been executed, the instrument returns to the previous remote control mode. 1110.3339.12 2.3 E-4 AMIQ Operation 3 Operation Control Elements AMIQ has no manual control elements except for the power on/off key. The I and Q signal outputs, the 3.5" disk drive and 3 LEDs are available on the front panel. AMIQ is remote-controlled (see chapter 6). I/Q signals can be simply and flexibly generated via the WinIQSIM program. AMIQ can also be controlled from Vector Signal Generator SMIQ (see section "Calculation of I/Q Modulation Signals" below). Indicating Elements (LEDs) Three LEDs are provided on the AMIQ front panel with the following functions: ON Is dimmed during the short test and lights fully during normal operation. The ON-LED flashes slowly while a data set is loaded into the AMIQ; it flashes quickly if an error occurred during the short test on power-up. Further information on the error can be obtained with :SYST:ERR?. CONTROL Lights when the host controller has switched the AMIQ to remote control. Flashes during long data transmissions. The remote-control source can only be changed (e.g. from IEC/IEEE bus to RS-232) when this LED is off. See also command *GTL. RUNNING Lights as soon as and as long as AMIQ reads data from the output memory and outputs them at the I and Q output sockets. 1110.3339.12 3.1 E-4 Operation AMIQ Calculation of I/Q Modulation Signals Control via WinIQSIM WinIQSIM The simplest and most flexible way to generate I/Q signals is to use the WinIQSIM program from Rohde & Schwarz. This program can be installed on a PC. The user interface permits convenient generation of the desired modulation waveforms and the corresponding control of AMIQ. IEC/IEEE bus / RS-232 • AMIQ can be controlled from the PC with WinIQSIM in two different ways: • Via a state-of-the-art IEEE-488 interface which can be controlled via an ® installed WINDOWS operating system (GPIB.DLL required). • Via the RS-232 interface. However, the data transmission rate here is lower than with control via the IEC/IEEE bus. Control via Vector Signal Generator SMIQ SMIQ If SMIQ is the RF source for vector-modulated signals, AMIQ can be controlled from SMIQ. An additional controller is not required in this case. Settings All main settings of AMIQ can be made in the AMIQ CTRL menu. The individual menu items are described in the SMIQ manual. 1110.3339.12 3.2 E-4 AMIQ Uses 4 Functional Description Uses Application AMIQ is mainly used for generating modulation signals for the I and Q inputs of a vector-modulated RF generator. Another application is testing modules or components with an I/Q interface. The control of I/Q interfaces is particularly simplified by fine tuning the delay, level and offset of the I/Q outputs. With this adjustment non-ideal characteristics of the circuits to be driven can be compensated for. Apart from the use as an I/Q signal source AMIQ allows all kinds of signals of programmable waveform to be generated at the I/Q outputs and at the four digital marker outputs of the instrument. Design AMIQ basically consists of a two-channel D/A converter and an output SDRAM for 4,000,000 samples (AMIQ model 03) or 16,000,000 samples (AMIQ model 04). The D/A converter clock can be adjusted in the wide range 10 Hz to 105 MHz. The technical data, however, are valid up to 100 MHz only. For operation at clock rates higher than 100 MHz note the restrictions described in the data sheet. Operation AMIQ has no local control elements and is remote-controlled via the serial interface or the IEC/IEEE bus. The output memory is also loaded via these interfaces. In addition, loaded waveforms can be temporarily stored on an internal hard disk and called up for the next output. Waveforms can also be loaded into AMIQ via the built-in disk drive. Stress Signals for I/Q Signals The error vector of vector-modulated RF signals mainly depends on the characteristics of the I/Q modulator and modulation generator. The following characteristics are essential for a small error vector: Amplitude imbalance Differences in amplitude between the I and Q channels lead to an offset in the constellation diagram and thus to a narrower eye width for the modulation. This can be illustrated by an I/Q vector diagram: Q Resulting modulation vector Error vector Ideal modulation vector I 1110.3339.12 4.1 E-6 Uses AMIQ Phase coincidence Phase differences and delay differences between I and Q also yield an error vector depending on the coding content. DC content DC offsets produce residual carriers in the generated RF signal. Each of the above stress factors in amplitude or phase leads to an inaccurate display of the desired vector component and thus to an error vector. Special Characteristics for Use of AMIQ as I/Q Modulation Source Symmetrical design In the development of AMIQ particular care was taken to keep the error vector as low as possible. The I and Q signal paths in the AMIQ are of identical design and the clock signals for the D/A converters for the two channels come from the same source. The programmed I and Q values for the D/A converter are always read together from the memory. Internal alignments The two AMIQ channels can be aligned for optimum balance with the aid of the built-in amplitude and phase meter without any external equipment being required. Internal fine tuning To compensate for possible amplitude and offset errors of the connected RF generator, amplitude and offset of the two channels can be fine tuned. Delay correction Small delay errors between the channels, as may be caused for instance by not completely identical cables between AMIQ and I/Q generator, can be compensated for in the AMIQ in a range from -1 ns to +1 ns with a resolution of 10 ps. External triggering The output can be started and stopped with an external trigger signal. Marker outputs 1110.3339.12 Four user-programmable and sample-accurately set marker outputs can be used, for instance, to drive external power ramping components. 4.2 E-6 AMIQ Basic Operating Modes Basic Operating Modes AMIQ has two different clock rate modes and two amplitude modes which should be selected as required for the desired clock rate and waveform: Clock rate mode 1 This mode is automatically set if a clock rate below 2 MHz is selected on AMIQ. SLOW The advantage offered by this mode is in the variation of the stored waveform length. In the case of AMIQ model 03, the waveform length can be varied from 24 to 4,000,000, in the case of AMIQ model 04 from 24 to 16,000,000 in steps of 1. For clock rates between 2 MHz and 4 MHz, both the SLOW and the FAST mode can be selected. The SLOW clock rate mode can be selected with the command CLOCK ,SLOW Clock rate mode 2 This mode is automatically set if a clock rate above 4 MHz is selected on AMIQ. FAST Please note that with this mode the waveform length can be varied only in steps of 4, i.e. in AMIQ model 03 from 24 to 4,000,000 and in AMIQ model 04 from 24 to 16,000,000. This means that the number of samples must be divisible by 4. For clock rates between 2 MHz and 4 MHz, both the SLOW and the FAST mode can be selected. The FAST clock rate mode can be selected with the command CLOCK ,FAST Amplitude mode Fix This mode is characterized by a maximum performance of the output signal and should preferably be used for generating vector-modulated signals. In the Fix mode, the level cannot be varied after D/A conversion, the amplitude of the output signal is determined only by the programming of the waveform D/A converter. When fully driven, the D/A converter yields an output amplitude of 0.5 V at the 50 Ω termination and thus corresponds to the maximum vector amplitude of the I/Q inputs of standard RF generators. For accurate matching to the modulation inputs of the connected RF generator, the amplitudes of the I and Q outputs of AMIQ can be separately adjusted for fullscale operation. The zero offset of the outputs can also be optimally adapted to the RF synthesizer by slight variations. Amplitude mode VAR This mode is intended for all applications for which the I/Q inputs of the RF generator or the module to be tested require I/Q input levels which cannot be set with the amplitude mode Fix. In the VAR mode the amplitude of the I/Q outputs can be set without the need to reprogram the respective waveform in the memory. The amplitude setting range is in this case twice as wide as in the Fix mode. In this mode also an analog inversion of the I and Q channels is possible. Because of the wide dynamic range for variable level tuning (20 dB), a poorer S/N ratio of the output signals may have to be accepted in this mode. 1110.3339.12 4.3 E-6 Signal Outputs AMIQ Signal Outputs Marker Outputs Control AMIQ is provided with four rear marker outputs, two for the I channel and two for the Q channel (see "Rear View" in chapter 1). These outputs are controlled by the waveform memory with a 16-bit word width for I and Q. In this case the two least-significant bits (LSBs) in the waveform memory are set for the I and Q channels. Bit assignment for the four marker outputs: Marker 1 LSB (bit 0) of I channel Marker 2 Bit 1 of I channel Marker 3 LSB (bit 0) of Q channel Marker 4 Bit 1 of Q channel When a waveform is loaded the markers are automatically programmed (see also "MARKer - Marker Management" in chapter 6). Uses Power ramping Marker outputs are typically used for controlling the power ramping of I/Q modulators to increase the switch-off dynamic range. With power ramping the pulse modulator input of the RF generator is used to switch off the RF signal synchronously with an I/Q symbol. Because of the delay difference between the I/Q inputs and the pulse modulator input of the RF generator, the marker signal in the I/Q data stream applied to the pulse modulator input has to be shifted. To ensure symbol-accurate power ramping, the marker outputs of AMIQ can be shifted with the remote-control command :MARKer [:LIST] irrespective of the programmed waveform (see "MARKer – Marker Management" in chapter 6). The changed marker settings can then be stored together with the waveform. Trigger generator The marker outputs may of course also be used separately, eg to use AMIQ as a universal trigger generator . Connector To obtain clear pulse shapes at the outputs, terminated lines should be connected to the marker outputs (50 Ω). The typical pulse amplitude at the termination is 2 V. This allows TTL inputs to be directly driven. Change of I/Q outputs to the rear Changing the I/Q outputs is possible only if option Differential Outputs (AMIQ-B2) is not fitted. 1110.3339.12 If the I and Q inputs of AMIQ are changed to the rear for rackmounting (AMIQB19), only the marker outputs 1 and 2 are available for markers. Marker outputs 3 and 4 are then used as Q and I outputs. 4.4 E-6 AMIQ Triggering Clock Output and Input Use of clock output At the AMIQ clock output, a squarewave signal is present whose frequency corresponds to the clock rate selected on AMIQ. By means of this output, AMIQ can be used as a clock generator for synchronization. The frequency can be set with high resolution (typ. 32 bits) between 10 Hz and 105 MHz. The frequency of 10 Hz, too, can be set with this resolution. Note: Connection of clock output Use of clock input To be able to activate this output, AMIQ must not be in the STOP state. The clock output should be terminated with 50 Ω. For the level, the same conditions apply as for the marker outputs. A double shielded cable has to be used because of the steep edges and the high harmonics content of the clock signal. External clock input is meaningful for AMIQ models 03 and 04 when operated in conjunction with option AMIQ-B3 (Digital I/Q Output). It enables two operating modes: • Integration of AMIQ into a system with a system clock • Feeding a DUT (e.g. D/A converter) with a spectrally pure external clock signal while maintaining clock/data synchronism For detailed information on external clock input see "External Clock" section in this chapter. Triggering The output of a waveform on AMIQ can be started either by remote control (see chapter 6, "ARM/TRIGger/ABORt – Triggering, Sequence Control") or by an external trigger signal. The trigger input is a TTL input and its edge or active level can be selected. There are the following modes: CONTinuous After the trigger is received, waveform output starts with the first point of the waveform and is repeated continuously. At the end of the waveform, output is continued immediately with the first point. SINGle After the trigger is received, waveform output starts with the first point of the waveform and ends with the last point. Then the I/Q outputs go to idle state. GATed After the trigger is received, waveform output starts with the first point of the waveform and is repeated continuously. After the end of the trigger event, waveform output is stopped and the I/Q outputs go to idle state. On the next trigger, waveform output starts with the first point of the waveform. OFF No triggering; no data are output. Any ongoing waveform output is stopped and the I/Q outputs go to idle state. 1110.3339.12 4.5 E-6 Triggering AMIQ The following applies to all trigger modes: • Before triggering and after the end of a trigger event, the I/Q outputs go to idle state (see chapter 6 "Waveform File Format" IDLE SIGNAL tag). • The time between the reception of a trigger signal and the start of waveform output is as follows: • Clock rate mode 1 (SLOW) • Mode 1: 220 ns +(1 sample + 20 ns) jitter • Clock rate mode 2 (FAST) • Mode 2: 11 samples + 1 sample jitter • The required pulse width for a reliable identification of the trigger signal is: • Clock rate mode 1 (SLOW) • min. 200 ns + 1 sample • Clock rate mode 2 (FAST) • min. 11 samples • 1 sample is the time elapsed between two subsequent output values. ! For detailed information on the various trigger modes and examples of application see chapter 6, command :TRIGger:MODE OFF | GATed | SINGle | CONTinuous 1110.3339.12 4.6 E-6 AMIQ I/Q Signal Adjustments I/Q Signal Adjustments In the AMIQ, level, offset and delay difference of I/Q outputs can be adjusted. The respective commands are contained in the :CORR (command) subsystem (see "SOURce – Hardware Settings " in chapter 6). These adjustments affect the positions marked in the block diagram below (Fig.4-1). Adjusting the Level In the Fix amplitude mode, the output level can be adjusted by approx. +/-10% with the aid of the following commands. Possible external gain differences can thus be compensated for. Command (example): Permissible range: :CORR:GAIN:I:FIX -0.1 :CORR:GAIN:Q:FIX 0.1 –1.0 to +1.0 • The automatic internal adjustment of the AMIQ is performed via the :CAL:AMPL? query. • In the FIX mode, the range –1 to +1 corresponds to an offset variation of approx. ±30 mV into 50 Ω. • In the VAR mode, the range –1 to +1 corresponds to an offset variation of approx. ±75 mV into 50 Ω. Adjusting the Offset The DC offset of the output levels can be fine-tuned in a range of approx. 30 mV using the following commands. The voltage is specified in V (terminated into 50 Ω). Command (example): :CORR:OFFS:I:FIX 0.3 :CORR:OFFS:Q:FIX -0.2 or :CORR:OFFS:Q:VAR -0.2 Permissible range: –1.0 to +1.0 • The automatic internal adjustment in the AMIQ is performed via the :CAL:OFFS? query. Adjusting the Delay For compensating slight differences in signal delay (caused eg by not completely identical cables or amplifiers), the I and Q output signals can be shifted against each other. The shift range is approx. ±1 ns at 10 ps resolution. The entry of positive values delays the I signal as against the Q signal. Command (example): :CORR:SKEW: -0.1 Permissible range: 1110.3339.12 –1.0 to +1.0 4.7 E-6 1110.3339.12 CLOCK IN/OUT 4.8 Controller Input :CORR:SKEW :CAL:ROSC DATA IN D Skew Adj A CLK Q-CLK 14 14 I-Ampl fix Adj D A Q-Ampl fix Adj A A :CORR:OFFS:Q:VAR D D A var Multiplier OUTPUT fix Amplifier, Attenuator fix :OUTP:Q Q-Offset var Adj I-Data Clock UBias(Q) OUTPUT Q CONTROL UBias(I) OUTPUT I AMIQ-B2 - Q-Data Multiplier var OUTPUT Amplifier, Attenuator Mode fix, var :OUTP:I I-Gain var I-Offset var Adj A Q-Gain var off, 25MHz, 2,5MHz, Extern Filter FILT EXT :OUTP:Q:AMPL :OUTP:Q:FILT D D off, 25MHz, 2,5MHz, Extern Filter :OUTP:I:AMPL :CORR:OFFS:I:VAR :OUTP:I:FILT Digital/Analog Converter Data Data Digital/Analog Converter A A I-Offset fix Adj Q-Offset D fix Adj A :CORR:OFFS:Q:FIX :CORR:GAIN:Q:FIX Q-Data 16 16 I-Data Waveform Memory ,Data Control 4 I-CLK D :CORR:GAIN:I:FIX (Q I if AMIQ-B19) 3 4 TRIGGER INPUT 2 10MHz A Ref Adj D Synthesizer, ClockDistribution 10 MHz REF IN/OUT MARKER 1 D Option AMIQ-B3 Option AMIQ-B2 Clk Clk Q I Q Q I I I Fig. 4-1 I :CORR:OFFS:I:FIX I/Q Signal Adjustments AMIQ AMIQ – Block Diagram Simplified block diagram of AMIQ E-6 AMIQ Measurement of Bit Error Rate Measurement of Bit Error Rate Option AMIQ-B1 allows the signal decoded by the DUT to be assessed. To do so the waveform memory is filled with a PRBS-modulated (pseudo random binary sequence) data sequence. The data are decoded by the DUT and forwarded to the AMIQ as clock and data signals. AMIQ synchronizes to the known PRBS sequence and counts the bit errors. The BER measurement can also be performed separately (with data from another source). Connector The clock and data signals supplied by the DUT must have TTL level and are applied to the bit error rate input, a 9-contact SUB-D connector at the instrument rear labelled BER. The pin assignment is as follows: SUB-D connector Adapter cord Part number 1110.3551.00 1,2,3,4,5 Ground Shield 6 Bit clock input "CLOCK" 7 Data input “DATA” 8 DAT ENABle input “DAT ENAB” 9 Restart “RES” The polarity of the clock and data signals, the PRBS polynomial and the integration time can be set with the respective remote-control commands. The input signals are not terminated in the AMIQ but applied to ICs type 74LVT14 via a 220 Ω resistor. 1110.3339.12 4.9 E-6 Measurement of Bit Error Rate AMIQ Signal Path and Waveform Test setup The desired signal is calculated with the aid of WinIQSIM and loaded into AMIQ. It is applied to an RF modulator via the I/Q outputs and forwarded to the DUT (device under test). The latter demodulates the received source bits and returns them to AMIQ together with a transfer clock. In the AMIQ, the data bits are checked for errors. The total of the transmitted bits and the faulty bits are counted. The quotient of error bits/total bits is the BER. PRBS data To be able to detect faulty bits in a BER measurement, the algorithm used for data generation must be known. Data are calculated with the aid of so-called pseudorandom binary sequences (PRBS). These are quasi-random bit sequences which are repeated according to the selected polynomial. An advantage of the PRBS data is that the bit error detector has only to know the calculation algorithm but not the total sequence. Furthermore, the analysis can be started anywhere in the bit stream, ie the bit-stream source and the analyzer need not be synchronized. To get familiar with the BER measurement and to check the BER measurement function in a simple way, a waveform file named PRBS9_E.WV is stored in the AMIQ waveform directory. This file contains a PRBS sequence with an error bit, which should produce an error indication of about 0.19% in WinIQSIM. The COMMENT tag of this waveform includes a short description allowing a fast check of the BER measurement function. {COMMENT: This is a waveform for checking the BER measurement. The waveform is applied to two marker outputs on the rear panel (no signal at I/Q output). To check the BER measurement, connect the adapter cord (Order No. 1110.3551.00) to the rear BER connector and the DATA cable to MARK1 and the CLOCK cable to MARK2. The signal at MARK1 (DATA) is a PRBS sequence with one error bit. To check the BER measurement with WinIQSIM, select 'Remote Control and Bert', 'Load HD File' and PRBS9_E, tick on Marker Ch.1 and Ch.2, select 'BERT' and start the BER measurement with 'Cont'. A bit error rate of approximately 0.19% should appear.} Transfer clock If the DUT does not provide a transfer clock, a marker channel can be programmed instead as a clock output. This is explained in the operating manual for WinIQSIM, chapter "Data Editor", and in the application manual "Software WinIQSIM for Calculating I/Q Signals for Modulation Generator AMIQ", chapter 5 "BER measurement with WinIQSIM and AMIQ", order no. 1027.3007.30. 1110.3339.12 4.10 E-6 AMIQ Measurement of Bit Error Rate Test Method Generation of PRBS data PRBS data are generated with the aid of a feedback shift register. The feedback points are determined by the calculation algorithm. An initial state selected at random yields exactly one subsequent state. The initial state and therefore the subsequent state occur only once in the whole data sequence. Feedback of data stream If the feedback shift register is filled with a data sequence at the beginning of a measurement and the register is then switched from "filling" to "feedback", the register will generate a data sequence which is exactly identical to the one it should receive from the DUT. Faulty bits can thus be identified and counted by comparing the received data to the results obtained from the shift register. This method has the advantage that the analysis can be separated from signal generation (logically and with respect to time). Consequently, delays caused by the DUT, the use of other PRBS sources and transmission over long distances with spatially separated transmitter and receiver, do not cause any problems. Faulty bits in output status If a bit error is already present in the output state (faulty bits are not detected during “filling“), the shift register starts from an incorrect position in the whole data string. As a result all subsequent states will be faulty. Since, statistically, every second bit is faulty, the BER will be about 50%. In this case a new measurement is started automatically so that the error goes unnoticed by the user. BER measurement with uninterrupted repetition of the random sequence The non-integrating BER measurement operates with random sequences which are stored in the AMIQ memory cyclically. The length of the random sequence is obtained from 2 to the degree of the polynomial less 1, ie PRBS9 has a length of 9 511 (2 is 512, less 1). The analysis data are interrupted by other data The BER measurement can be set with the command BERT:SETup:RESTart INTernal and output on the CLOCK and DATA line. The data bits carry "extraneous" data such as sync, preambles, other channels etc in addition to the PRBS data. To identify the data to be evaluated, the BER measurement must be provided with a validity signal (DAT ENABle input) apart from the actual data. This DAT ENABle signal is generated either by the DUT or provided by the AMIQ as a marker channel. The DAT ENABle signal can be defined in the data editor when the data are generated in the WinIQSIM. It may be necessary to match the timing of the marker signal to the data of the DUT (see below). The BER measurement using the AMIQ should be set to the use of a validity signal (DAT ENABle); for this the polarity in menu AMIQ -> Remote Control and BERT is set. The setting DAT ENABle = high signifies that data from the DUT are counted and subjected to a BER measurement only if the DAT ENABle input is at 1. 1110.3339.12 4.11 E-6 Measurement of Bit Error Rate BER measurement with interrupted random sequence – integrating BER measurement AMIQ Depending on the type of data, oversampling and the finite memory length of AMIQ, it may happen that the generated random sequence is not cyclically repeated at the memory wrap-around but that a break occurs at this point. In an ordinary BER measurement which relies exclusively on the CLOCK and DATA signals, this break would cause a loss of synchronization and thus about 50% of faulty bits. A random sequence with a discontinuity can be handled with the integrating BER measurement and is switched on by means of the BERT:SETup:RESTart EXTern command. The BER measurement must be halted in time and re-started at the beginning of the data sequence. Halt and start is effected using a signal at the RES input (pin 9 of D-sub connector): A logic 1 at this input resets the BER measurement, a 0 starts the measurement. It is useful to link this input with a marker channel of the AMIQ in which a single 1 (about 2 bits long) is coded at the beginning of the data sequence. The marker channel then starts the BER measurement anew for each memory cycle (of the discontinuity). If the data signals are interrupted from other data (eg preambles), the latter can result in bit errors. The BER measurement can be interrupted for such data with the aid of the DAT ENABle input on a different marker channel. In the integrating BER measurement the individual measurements are added up under the control of a signal at the RES INPUT until the predefined total number of data or errors bits are attained or exceeded. Complex measurement and signal sequences of this type cannot be easily generated manually so with the use of the Windows software WinIQSIM from R&S it is possible generate data sequences for the BER measurement. It can thus be ensured that the DAT ENAB and RES signals are timed correctly for the data signals and discontinuity. See also chapter titled "Data Editor" in the WinQSIM manual as well as application manual "Software WinIQSIM for Calculating I/Q Signals for Modulation Generator AMIQ", chapter 5 "BER measurement with WinIQSIM and AMIQ" Order No. 1027.3007.30. Note: 1110.3339.12 The flexible programming of the test hardware permits other BER measurement methods to be used, eg comparison with output pattern, masking certain time and data ranges. Contact your local R&S sales office for further information. 4.12 E-6 AMIQ Measurement of Bit Error Rate PRBS Polynomials A feedback shift register is used for generating and checking the PRBS. The feedback is switched n depending on the polynomial used. The sequence length of a generator is 2 - 1, n being the degree of the polynomial. EXOR Fig. 4-2 EXOR EXOR PRBS Polynomials PN generator n a1 a2 a3 Output Applicable standard PN9 9 4 - - non-inverted ITU-T Rec. O.153 Fascicle IV.4 PN11 11 2 - - non-inverted ITU-T Rec. O.152 Fascicle IV.4 PN15 15 1 - - inverted ITU-T Rec. O.151 Fascicle IV.4 PN16 16 5 3 2 non-inverted -- PN20 20 3 - - non-inverted ITU-T Rec. O.153 Fascicle IV.4 PN21 21 2 - - non-inverted -- PN23 23 5 - - inverted ITU-T Rec. O.151 Fascicle IV.4 Measurement Result, Accuracy, Measurement Time Value range: -2 The measured BER (ie ratio of faulty bits to total bits) is normally between 10 and -9 10 . This means that a great number of bits may have to be checked before a faulty bit is detected. Because of the great number of bits involved the measurement time is usually very long. Since 32-bit-wide counters are used for the total bits and the error bits, the 9 maximum measurement time is 4.29⋅10 bits. Statistics The BER measurement measures statistical bit errors, ie errors which do not occur at regular intervals but at random. Although a single measurement determines the exact number of errors in the measured range, a reliable BER rate can only be obtained when a sufficient number of errors occurs in the observed range with the result that the single BER measurement result approaches the true error rate with high probability . End criteria To keep the measurement time short with low and high bit error rates, two end criteria have been defined in AMIQ for the BER measurement. • Criterion 1: Total number of bits The measurement is terminated when the total of the specified bits is reached. Due to this criterion the BER measurement is reliably stopped after the specified number of bits even if no error or only a few errors were detected and 1110.3339.12 4.13 E-6 Measurement of Bit Error Rate AMIQ the measurement result is not very accurate (few bit errors). • Criterion 2: Number of faulty bits The measurement is terminated when the specified number of bit errors is detected. With this criterion, the measurement is rapidly terminated when high bit error rates occur. Since a great number of errors is counted, the measurement is relatively accurate. The two criteria are used together. The criterion which finally yields a valid result is indicated by AMIQ after a result query. Interruption of measurement At the end of a measurement, the restart of a new one is delayed until the first measurement result has been queried with BERT:RES?. The resulting brief measurement interruption is irrelevant because the subsequent measurement will be synchronized within 24 data bits. Possible Problems with BER Measurement and Related Solutions Fault Possible cause Fault description/remedy BER measurement does not synchronize No signals from DUT received or the signal level is not correct. Ø Read the activity of the inputs used for the BER measurement on the WinIQSIM or SMIQ display. BER measurement using PRBS sequences was not activated in AMIQ. Ø Activate the BER measurement using PRBS sequences once before the measurement is started. This is done with command BERT:SEL "PRBS". This command ensures that the measurement hardware is loaded with the correct configuration file. Then switch AMIQ off and on again to load the configuration file to the measurement hardware. The selected PRBS is not correct. Normally, the PRBS of the data is transmitted together with the waveform file and used as a default setting. If the PRBS is changed, the BER measurement cannot synchronize to the data (because the calculation polynomial is not correct). A green lamp (on the screen) next to the name (clock, data) indicates that the respective line is active. A wrong clock edge is used for Ø Check the bit clock signal, the data signal and the DAT ENABle triggering violating setup or signal, if any, on an oscilloscope. hold times. The fault may also be caused by reflections on the clock line, which switch the data signal twice into the BER measurement; see section Avoid Reflections in the BER Measurement on page 4.17. 1110.3339.12 Incorrect polarity of data signal (or DAT ENABle signal). In this case the PRBS cannot synchronize either. Note that an inversion of the output signal specified for some cases by the PRBS standard is performed automatically upon PRBS selection. Manual inversion of the data signal is thus not required. A bit error occurs during synchronization (eg the synchronization time is nine data bits with PRBS9) The BER measurement is started at a wrong position so that about 50% of the subsequent data bits are identified as faulty. This "incorrect" result is rejected by the AMIQ software and the measurement is automatically repeated (upon the next query by WinIQSIM or SMIQ). 4.14 E-6 AMIQ Measurement of Bit Error Rate Fault Possible cause Fault description/remedy No clock received from DUT When testing RF components, the clock recovery may no be available. An external clock is however required for clocking the data during the BER measurement An AMIQ marker channel can be used instead of the clock from the clock recovery circuit. To do so proceed as follows: Ø Connect the marker channel (eg marker 1) to the clock input (pin 7) of the BER measurement. Ø Program a 0-1 transition in this marker channel for each data bit to be evaluated. This method cannot be used with modulations using a value >1 (eg QPSK) as several bits are coded per symbol. It may be possible to select a bit pattern in the marker channel which permits a clock edge to be generated for each bit in the symbol. In this case a sufficiently high oversampling value must be selected. BERT is selected by WinIQSIM in the data editor for the generation of a suitable marker signal. For details refer to the WinIQSIM manual. Measured BER too high The data are switched with the wrong clock edge and/or the eye pattern of the data is not optimally met. BER measurement [FW1]does not synchronize . Ø Check the clock/data relationship by means of an oscilloscope and set optimum timing. Ø If the clock is derived from an AMIQ marker channel, shift the channel by a few sampling points (see OUTPUT:MARKER :DELAY). If data that are not cyclically repeated (ie when an interruption occurs at the memory wrap-around), the measurement will identify about 50% of the bits as faulty after the wrap-around. Ø Make sure that the measurement is optimally started at the beginning of the sequence via the signal on the REStart line (see "BER measurement with interrupted random sequence – integrating BER measurement" in section "Test Method" on page 4.11). Further Hints and Tricks Correction of • If all signals come from the DUT, the delay of the DUT will not cause any problems. In this case the BER measurement is performed completely independent of the DUT delay AMIQ signal output. After the start of the measurement, the BER is automatically synchronized to the applied data. • If the clock, DAT ENABle or restart signals are not supplied by the DUT but generated on the AMIQ marker outputs and the signals are used together with the clock or data from the DUT, delays may occur which have to be corrected. The DUT will normally require a certain time to return the data bits to AMIQ. This delay may be less than one bit. The signal on the marker channel is directly applied from the output socket to the input for the BER measurement and is therefore not delayed. The signals on the marker channels (eg the clock signal) must therefore be shifted with reference to the I/Q output data so that they are optimally time-synchronized. This can be done in two ways: Ø Shift the marker of a loaded trace by a specified number of samples using the function OUTPUT:MARKER :DELAY . Ø A pattern is used for generating the clock signals, which defines the sequence of 010 transitions in the marker channel. Modify this clock pattern to shift the active clock edge (referred to the I/Q output). Then: Ø Check the timing of the BER signals on an oscilloscope. Ø Connect the marker channel containing a clock signal to the clock input (pin 7) of the BER IC. 1110.3339.12 4.15 E-6 Measurement of Bit Error Rate AMIQ Installation of Option AMIQ-B1, BER Measurement If the instrument is ordered with option AMIQ-B1, the option comes as active and ready for operation. If the option is subsequently ordered, proceed according to the instructions supplied with the option. If these instructions are not available, follow the instructions given below: Ø Connect AMIQ to a controller. Ø Activate option AMIQ-B1 in the AMIQ. To do so send command SYST:OPT AMIQB1,xxxxxxxx to AMIQ, xxxxxxxx being the key number. The key number is supplied together with the option. The option needs not be reactivated after a firmware update. The activation command can be sent to AMIQ under Remote Control and BERT -> Test and Adjustment -> Send Command to AMIQ in the AMIQ menu of WinIQSIM. Ø To activate the BER measurement using PRBS sequences, activate this measurement mode with command BERT:SEL “PRBS“. This prepares the loading of the measurement hardware with the correct configuration file. AMIQ has to be switched off and on again to load the configuration file to the measurement hardware when the measurement is started. This selection command has to be sent only once. Once the configuration has been set, it is preserved even after a firmware update. Activation is checked when a BER measurement is called in WinIQSIM and carried out automatically if not done before. 1110.3339.12 4.16 E-6 AMIQ Measurement of Bit Error Rate Avoid Reflections in the BER Measurement RS 232 X 11 X 12 LPT /LPT PARALLEL X 13 X 10 100...120 / 200...240 V 50...60 Hz 150 VA 625 IEEE 488 SCPI F 1/ F 2: IE C 127 - T 4.0 H / 250 V AUTO P OWER SELECTION REF CLK Q Q FILT 1 2 MARK 3 4 MARK I I FILT TRIG BER Clock With this test setup using BNC cables, no probes are needed. There are no reflections if the BNC cables are directly connected to the oscilloscope by means of T connectors. 50 Ohm BNC cable Data BER test cable REF CL OCK Oscilloscope DATA MASK RES RS 232 X 11 X 12 LPT /LPT PARALLEL X 13 100...120 / 200...240 V 50...60 Hz 150 VA X 10 625 IEEE 488 SCPI F 1/F 2: IE C 127 - T 4.0 H / 250 V AUTO P OWER SELECTION REF REF CLK Q FILT Q 1 MARK 2 3 MARK 4 I FILT I TRIG BER Clock Data BER test cable CLOCK DATA No reflection problems if the signals are tapped off with probes. MASK RES Oscilloscope RS 232 X 11 X 12 LPT /LPT PARALLEL X 13 X 10 100...120 / 200...240 V 50...60 Hz 150 VA 625 IEEE 488 SCPI F 1/F 2: IEC 127 - T 4.0 H / 250 V AUTO POWER SELECTION REF REF CLK Q FILT Q 1 MARK 2 3 MARK 4 I FILT I TRIG BER Clock If the oscilloscope is connected by means of BNC cables as shown in this figure, the result of the BER measurement might be impaired because of reflections (spurious signals) caused by the long branch lines to the oscilloscope. Data BER test cable CLOC K DATA MASK RES 50 Ohm BNC cable Oscilloscope CLOCK New BER test cable are labelled DAT ENAB instead of MASK The BER test cable is part of the option AMIQ-B1. It can be ordered as a replacement part with the stock no. 1110.3551.00. The pin assignment is described in section "Connector" in this chapter. DATA MASK RES Fig. 4-3 Avoid reflections in the BER measurement 1110.3339.12 4.17 E-6 Application Example for Option Differential Outputs AMIQ Application Example for Option Differential Outputs (AMIQ-B2) Option Differential Outputs (AMIQ-B2, stock no. 1110.3700.02) is a hardware option ready for operation immediately after being fitted by an R&S service technician. Essentially, a PC board must be installed and the front panel of AMIQ must be replaced by another one containing 4 output connectors. Control of the differential outputs by WinIQSIM is supported starting with version 2.10 of both products. Advantages of differential outputs compared to asymmetric outputs Manufacturers equip IQ modulator components with differential inputs mainly to obtain improved technical data concerning port insulation, spurious responses and harmonics. Option AMIQ-B2, Differential Outputs, allows to feed these components correctly with symmetric signals in order to make full use of the technical specifications of the modulator ICs. An operating voltage of +5 V, recently also +3,3 V, referred to ground is used. As a consequence of this asymmetric power supply, the DC level (= operating point of the corresponding input) must be set to the center of the operating voltage range by means of an external electric network. The additional expense to install the external electric network is saved by option AMIQ-B2. This option allows to superimpose a DC voltage ranging from –2.5 V to + 2.5 V (called bias voltage in the following) upon the symmetric I or Q signal (highimpedance input). The following application example shows the function of the option combined with the AMIQ basic unit. + I I + Corr UBias(I) I + Corr + Q I OUTP:I:BIAS -2.5 ... 2.5V I + Corr Offset Q User Correction CORR:OFFS:Q:FIX|VAR -1 ... +1 I+Corr+UBias + I+Corr+UBias + I Offset I User Correction CORR:OFFS:I:FIX|VAR -1 ... +1 I DUT Q + Corr Q+Corr+U Bias + RF carrier Q OUTP:Q:BIAS -2.5 ... 2.5V Q + Corr UBias(Q) Q + Corr Q+Corr+U Bias + I Example Q AMIQ-B2 I/Q modulator component AMIQ I/Q modulated RF carrier Fig. 4-4 Application block diagram of option AMIQ-B2 1110.3339.12 4.18 E-6 AMIQ Application Example for Option Differential Outputs Functions of the structure shown above: • AMIQ provides the modulation signals I and Q (asymmetric). • Option AMIQ-B2 outputs these signals together with the inverted signals I and Q. The signals control the modulator chip. • To set the operating point of the modulator component (DUT) a DC voltage UBias that can be adjusted individually for I (I) and Q (Q) is superimposed upon the modulation signals. • To optimize the RF carrier suppression an additional correction voltage (Corr), again individually adjustable for both channels I and Q, can be superimposed upon the initial signals. Inclusion of option AMIQ-B2 causes the correction voltages to be set in positive direction at the non-inverting outputs, in negative direction at the inverting outputs. This doubles the absolute value of the correction between I and I or between Q and Q. Should it be necessary, a difference between the best operating points for I and Q of the modulator chip can be balanced. The bias voltage of the option represents basically a „common mode“ voltage for the four signal outputs while the offset voltage selected via „user correction“ in the AMIQ basic unit represents a balance setting between the inverting and the non-inverting output. Once the operating point of the DUT is set via Ubias it can be simply preserved by selecting an output impedance of 50 Ω for the OFF state even if the signal level is switched off. If „High Impedance“ is selected, the bias voltage will be set to zero whenever the output is switched off. 1110.3339.12 4.19 E-6 AMIQ Model 03 / 04 AMIQ AMIQ Model 03 / 04 AMIQ models 03 and 04 can be fitted with the option AMIQ-B3 (digital I/Q output) and supplied with an external clock, see also "Option AMIQ-B3 (digital I/Q output)" and "External Clock" in this chapter. AMIQ model 04 is provided with a much larger memory and can thus store traces up to 16 000 000 I/Q values. Compared with model 03 (4 000 000 I/Q values) model 04 has four times greater memory capacity. Apart from that there is no difference between the two models. 1110.3339.12 4.20 E-6 AMIQ Digital I/Q Output Option AMIQ-B3 Digital I/Q Output Option AMIQ-B3 The digital I/Q output option is available for models 03 and 04 and supplies the 16-bit data bus for both channels I and Q at a 68-pin front-panel connector on the AMIQ basic unit. Of the 16 bits the two least significant bits (d0 and d1) are used as marker signals and the remaining 14 bits for signal generation. This data bus also drives the two internal 14-bit main DACs. The associated bit clock is supplied in addition. Using version 3.10 and higher of the program WinIQSIM the digital output can be activated (ON) or deactivated (OFF) as long as pin 66 at the connector is high (see pin allocation). If this pin is low, then the outputs are permanently of high-impedance. This avoids latch-up effects of the following circuit in the absence of supply voltage. Traces calculated with versions < 3.10 of WinIQSIM had previously a width of 14 bits, ie d0 and d1 were fixed at 0 and d2 was rounded by means of d1. Data bits d0 and d1 could be used as marker bits. Each trace generated by WinIQSIM version 3.10 and higher has a resolution of 14 or 16 bits, depending on the selected output resolution (see "Operation"): • For an output resolution of 8 to 14 bits WinIQSIM generates traces with a generation resolution of 14 bits. • For an output resolution of 15 or 16 bits WinIQSIM generates traces with a generation resolution of 16 bits. Example: A 12 bit output resolution is set in WinIQSIM. WinIQSIM calculates and transfers the IQ data with a resolution of 14 bits (so the marker signals remain accessible). In the {RESOLUTION: x,y} tag, the trace contains the generation resolution (14 bits) as well as the output resolution (12 bits). When this trace is loaded into the output RAM of the AMIQ, it is automatically quantized to 12 bits. Still it is possible to increase the output resolution of the trace to a maximum of 14 bits later without calculating the trace again. Each trace generated by WinIQSIN version 3.10 or higher has a resolution of 14 or 16 bits. From this version up each trace contains the new {RESOLUTION: x,y} tag with • 'x' = generation resolution (bit width of trace generated by WinIQSIM) and • 'y' = output resolution (bit width of trace output by AMIQ). Traces with a generation resolution of 14 bits allow the use of markers without any restriction. However no markers are available with traces of 16-bit generation resolution because data bits d0 and d1 represent the least significant bits of the I/Q values. When markers are active and a trace with a generation resolution of 16 bits is loaded, the markers are switched off and marker commands are rejected. Decreasing the output resolution with the command OUTPut:RESolution 8...16 does not allow the use of markers since the reduction of the resolution is achieved mathematically with a rounding logarithm by setting data bits d0 and d1 to 0 which means that there can be no valid markers. Although loading marker list is theoretically possible after the reduction of the output resolution to ≤ 14 bits, no use was made of this for the sake of clarity of operation – the decisive factor for the execution of marker commands is solely the resolution of generation. A generation resolution of 16 bits has no relevance for the I/Q outputs; in analog operation same as before d2 ... d15 go to the 14-bit converter. The higher resolution can be fully exploited only together with the digital I/Q option (AMIQ-B3) and permits a 12-dB higher resolution than at the analog output. The output resolution of a trace can subsequently be modified with the IEEE 488 command OUTPut:RESolution 8...16 and must always be ≤ the generation resolution. The command OUTPut:RESolution 8...16 can be used independently of the digital I/Q output option (AMIQ-B3) and can be quite useful to reduce the output resolution of the analog outputs to observe the DUT's response. 1110.3339.12 4.21 E-6 Digital I/Q Output Option AMIQ-B3 AMIQ Reducing the output resolution has the effect of setting unused bits to 0 and rounding the value. The value is always output MSB-justified at the digital I/Q output and at the 14-bit D/A converter. To synchronize the digital data output via the digital I/Q output option (AMIQ-B3) with a system clock, AMIQ is to be driven with an external clock. To do this, the clock connector on the rear of the AMIQ basic unit is to be set from output to input in the WinIQSIM program (see section "External Clock" on page 4.26, "Operation"). To be able to work with a bit clock greater than 25 MHz to 30 MHz, it is recommended to plug the DUT directly to the 68-pin connector or, if possible, to use short connecting cables to avoid interfering reflections. In such cases, data and clock lines should be terminated with resistances of 120 Ω to 150 Ω. Operation of Digital I/Q Output Option (AMIQ-B3) using WinIQSIM Modulation Generator AMIQ is operated via the WinIQSIM program (versions required: WinIQSIM = 3.10). The analog and digital outputs can be activated independently from one another. The AMIQ can be set in the following way: • • Click the REM button in the top bar or open the menu item ”AMIQ” and ”Remote Control and BERT...”. The AMIQ operator window now appears. The digital I/Q output can be activated or deactivated following the selection of the ”HardwareSetting” submenu under "Digital Output". 1110.3339.12 4.22 E-6 AMIQ Digital I/Q Output Option AMIQ-B3 Pin Allocation of Digital I/Q Outputs Pin 35 Pin 68 Digital Output Pin 1 Pin 34 Fig. 4-5 Pin allocation of digital I/Q outputs The output pins of the option has the following features: Pin 66: the wiring of this pin (PWR_SENSE) enables Low (<0.8 V) = outputs disabled, of high impedance High (>2.4 V) = outputs enabled Pin 67: a supply voltage (+3.3 V or +5 V) is provided for an external circuit. The magnitude of VCC depends on the wiring at Pin 68. Pin 68: the wiring of this pin determines the supply voltage level at pin 67. Low (<0.8 V) = +5 V High (>2.4 V) = +3.3 V The high level of data, marker and clock signals adapts to the selected supply voltage level. Further allocation of pins: Pins 1 to 16: data I0 to I15 Pins 17 to 32: data Q0 to Q15 Pin 33: bit clock Pin 34: inverted bit clock Pins 35 to 65: ground or disables the outputs: (I0 ≡ marker 1, I1 ≡ marker 2) (Q0 ≡ marker 3, Q1 ≡ marker 4) Brief Specifications Table 4-1 Specifications of option AMIQ-B3 Output 68-contact connector (mini D-sub, half pitch) Number of channels 2 (one each for I and Q) Resolution 8 to 16 bits (selectable), no marker output for wordwidth 15 or 16 Max. clock frequency 100 MHz (at clock frequencies greater than 40 MHz, the 20 to 25 ns AMIQ delay between the input clock and the output data must be taken into account) Output impedance Approx. 30 to 50 Ω Data output level +3.3 or +4.0 V to +4.5 V (LVT or ABT high level) VCC level +3.3 V or +5 V/0.3 A (selectable) Clock output Normal and inverted polarity 1110.3339.12 4.23 E-6 Digital I/Q Output Option AMIQ-B3 AMIQ Technical Details d15 d2 d1 d0 Data bus d15 ... d0 d15 ... d2 Marker outputs 14-bit D/A converter Analog I/Q output d0 ≡ marker 1, d1 ≡ marker 2 d0 ≡ marker 3, d1 ≡ marker 4 Channel I: Channel Q: Fig. 4-6 Digital I/Q output Technical implementation of digital I/Q outputs 1110.3339.12 4.24 E-6 AMIQ Digital I/Q Output Option AMIQ-B3 IEEE 488 Commands The following IEEE 488 commands apply to option AMIQ-B3: Table 4-2 IEEE 488 commands for option AMIQ-B3 Section (see chapter 6) IEEE 488 commands OUTPut – hardware settings OUTPut:DIGital ON|OFF OUTPut:RESolution 8 ... 16 OUTPut:MARKer ON|OFF OUTPut:MARKer :DELay Common commands *IDN? *OPT? SYSTEM – different settings SYSTem:OPTion? DIAGnostic – hardware diagnosis DIAG:ABO:ID? Marker management MARKer [:LIST] Trace file format Tag {RESOLUTION: x,y} 1110.3339.12 4.25 E-6 External Clock AMIQ External Clock Brief Description AMIQ 03 and 04 can be fed with an external clock at the rear-panel connector CLK. The AMIQ can thus be operated synchronously by means of an external clock. Using an external clock together with option AMIQ-B3 (digital I/Q output) enables the following operating modes, for example: AMIQ System clock AMIQ B3 Integrating an AMIQ into a system with system clock DUT Data D A Internal AMIQ clock Fig. 4-7 Integration of the AMIQ into a system with system clock Advantage clock frequencies of up to 100 MHz, clock and data synchronous with external clock Disadvant age clock may become noise through coupling in AMIQ Feeding a DUT (eg D/A converter) with a spectrally clean external clock whilst retaining clock/data synchronization Signal delay 20 to 25 ns AMIQ AMIQ B3 DUT Data D A AMIQ clock unused System clock Delay equalization required from 40 MHz System clock Fig. 4-8 Feeding a DUT with a spectrally pure external clock Advantage clean clock for DUT Disadvantage clock frequencies of only up to 40 MHz possible clock frequencies of 40 to 100 MHz require delay equalization of the clock line to the DUT 1110.3339.12 4.26 E-6 AMIQ External Clock Operation Modulation Generator AMIQ is operated via the WinIQSIM program (versions required: WinIQSIM = 3.01BETA, AMIQ-FW = 3.0BETA). • • Click the REM button in the top bar or open menu item ”AMIQ” and ”Remote Control and BERT...”. The AMIQ operator window now appears. The "Clock Mode" can be selected under "Source, Trigger ..." following the selection of the ”Hardware Setting” submenu. IEC/IEEE-bus command For IEC/IEEE-bus command and frequency ranges see chapter 6: SCLock INTernal|EXTSlow|EXTFast. 1110.3339.12 4.27 E-6 Multisegment Waveform AMIQ Multisegment Waveform Application and structure In particular when the AMIQ is used in automatic test equipment (ATE), the components to be tested must be operated by a wide variety of test signals. To minimize the test time, the change between the individual test signals must be as rapid as possible. Loading the new signals from the AMIQ hard disk should be avoided, if possible. The multisegment waveform (MWV)), which is implemented in the AMIQ as of firmware version 4.00, meets this requirement. Superficially, an MWV is similar to a standard waveform in the AMIQ. Its maximum length depends on the AMIQ model (4 Msamples with AMIQ03, 16 Msamples with AMIQ04). What makes the MWV special is the fact that it can consist of up to 30 partial traces, the segments. Each segment can be considered an independent waveform (with its own marker assignment and clock rate). The complete waveform is loaded into the output RAM of the AMIQ, where a segment can be selected and output. It is possible to change between the segments (partial signals) without reloading the output RAM by simply specifying a new segment index. A rapid change between the partial signals, and, consequently, an acceleration of the test procedure is thus possible. The structue of the AMIQ output RAM requires the multisegment waveforms to comply with the following conditions : • Maximally 30 segments. • The minimum length of each segment must be 128 ksamples (= 131.072 samples). • The segment length in samples must be a multiple of 4. • For a fast segment change, it is recommended that all segments be generated with the same clock rate. The clock rate can easily be changed in each new segment. Note: Use the WinIQSIM operator program as of version 3.80 for easy generation of a multisegment waveform from various partial traces. The AMIQ ensures compliance with these conditions. The user only needs to specify which standard waveforms in the AMIQ he or she would like to combine to form a multisegment waveform. The AMIQ automatically meets the conditions placed on length by repeating the basic waveform of a segment. Once a multiwaveform has been generated, it can be loaded and output like any other waveform. 1110.3339.12 4.28 E-6 AMIQ Multisegment Waveform Partial trace 1 MMEMory:MWV:FIRStsegment , , MMEMory:MWV:APPend , , MMEMory:LOAD RAM, Resulting MWV in output RAM Partial trace 2 Segment 1 Segment 2 Segment 3 Partial trace 3 Automatic repetition of partial trace Output signal ARM TRIGger:MWVSegment 3 Fig. 4-9 Generation of an MWV from partial traces IEC/IEEE bus commands For a detailed description of the IEC/IEEE bus commands, refer to chapter 6. • Generating an MWV MMEMory:MWV:FIRStsegment 'Source waveform multi segment waveform file','Comment' file to start','Destination MMEMory:MWV:APPend 'Source waveform file to append','Destination multi segment waveform file','Comment' • Deleting segments of a multisegment waveform MMEMory:MWV:DELete 'Multi Segment Waveform file', . • Output of multisegment waveform segments MMEMory:LOAD RAM 'Multi Segment Waveform file' ARM und TRIG TRIGger:MWVS • Restrictions during the MWV output The following minor restrictions apply during an MWV output: • The GATED trigger operating mode (TRIGger:MODe GATed) is not available. • Marker lists (OUTPut:MARKer<1..4>:LIST '0-100:1;200-400:0') cannot be subsequently taken into account. • Shifting the marker signals (OUTPut:MARKer<1..4>:DELete ) is not possible. • The output resolution (OUTPut:RESolution ) of the I/Q signal cannot be subsequently modified. • The clock frequency (SOURce:CLOck ) cannot be subsequently modified. These restrictions are referred to in chapter 6, in the commands concerned. 1110.3339.12 4.29 E-6 AMIQ Short Introduction 5 Remote Control - Basics The instrument is equipped with an IEC bus interface according to standard IEC 625.1/IEEE 488.1 and a RS-232 interface. The connectors are located at the rear of the instrument and permit to connect a controller for remote control. The instrument supports the SCPI version 1996.0 (Standard Commands for Programmable Instruments). The SCPI standard is based on standard IEEE 488.2 and aims at the standardization of device-specific commands, error handling and the status registers (see section "SCPI Introduction"). This section assumes basic knowledge of IEC bus programming and operation of the controller. A description of the interface commands can be obtained from the relevant manuals. The requirements of the SCPI standard placed on command syntax, error handling and configuration of the status registers are explained in detail in the respective sections. Tables provide a fast overview of the commands implemented in the instrument and the bit assignment in the status registers. The tables are supplemented by a comprehensive description of every command and the status registers. Detailed programming examples of the essential functions can be found in chapter 7, "Programming Examples". The examples for IEC bus programming are all written in QuickBASIC. Note: In contrast to instruments with manual control, which are designed for maximum possible operating convenience, the priority of remote control is the "predictability" of the device status. This means that when incompatible settings are attempted, the command is ignored and the device status remains unchanged, i.e. other settings are not automatically adapted. Therefore, IEC/IEEE-bus control programs should always define an initial device status (e.g. with the command *RST) and then implement the required settings. Short Introduction Chapter 2, "Getting Started", outlines a short introduction to remote control of the AMIQ. The chapter also describes how the transfer parameters for RS-232 and the IEC bus can be set without using remote control commands. Messages The messages transferred via the data lines of the IEC bus and the serial interface (see section "Hardware Interfaces" in this chapter) can be divided into two groups: - interface messages device messages 1110.3339.12 5.1 E-5 Messages AMIQ Interface Messages Interface messages are transferred on the data lines of the IEC bus, the ATN control line being active. They are used for communication between controller and instrument and can only be sent by a computer which has the function of an IEC bus controller. Interface commands can be further subdivided into - universal commands addressed commands Universal commands act on all devices connected to the IEC bus without previous addressing, addressed commands only act on devices previously addressed as listeners. The interface messages relevant to the instrument are listed in section "Hardware Interfaces" in this chapter, subsection "Interface Messages". There are no interface message for the RS-232 interface. Only the "Device Clear" is emulated by the BREAK-signal of the serial interface (see section "Interface functions" on page 5.25). Other interface messages are replaced by device messages (e.g. "*GTL"). Device Messages (Commands and Device Responses) Device messages are transferred via the data lines of the IEC bus (the "ATN" control line not being active) or via the serial interface. The ASCII code is used. The device messages are largely identical for the two interfaces. A distinction is made according to the direction in which device messages are transferred: – Commands are messages the controller sends to the instrument. They operate the device functions and request information. The commands are subdivided according to two criteria: 1. According to the effect they have on the instrument: Setting commands cause instrument settings such as reset of the instrument or setting the output level to 1 Volt. Queries cause data to be provided for output on the IEC bus, e.g. for identification of the device. 2. According to their definition in standard IEEE 488.2: Common commands are exactly defined as to their function and notation in standard IEEE 488.2. They refer to functions such as management of the standardized status registers, reset and selftest. Device-spec. commands refer to functions depending on the features of the instrument such as frequency setting. A majority of these commands has also been standardized by the SCPI committee (cf. section "SCPI Introduction"). – Device responses are messages the instrument sends to the controller after a query. They can contain measurement results, instrument settings and information on the instrument status (cf. section "Responses to Queries"). Structure and syntax of the device messages are described below. The commands are listed and explained in detail in chapter 6. 1110.3339.12 5.2 E-5 AMIQ Structure and Syntax of the Device Messages Structure and Syntax of the Device Messages SCPI Introduction SCPI (Standard Commands for Programmable Instruments) describes a standard command set for programming instruments, irrespective of the type of instrument or manufacturer. The goal of the SCPI consortium is to standardize the device-specific commands to a large extent. For this purpose, a model was developed which defines the same functions inside a device or for different devices. Command systems were generated which are assigned to these functions. Thus it is possible to address the same functions with identical commands. The command systems are of a hierarchical structure. Fig. 5-1 illustrates this tree structure using a section of command system SYSTem, which allows to define various device settings. Most of the other examples concerning syntax and structure of the commands are taken from this command system. SCPI is based on standard IEEE 488.2, i.e. it uses the same syntactic basic elements as well as the common commands defined in this standard. Part of the syntax of the device responses is defined with greater restrictions than in standard IEEE 488.2 (see section "Responses to Queries"). Structure of a Command The commands consist of a so-called header and, in most cases, one or more parameters. Header and parameter are separated by a "white space" (ASCII code 0 to 9, 11 to 32 decimal, e.g. blank). The headers may consist of several key words. Queries are formed by directly appending a question mark to the header. Note: The commands used in the following examples may not in every case be implemented in the instrument. Common Commands Common (=device-independent) commands consist of a header preceded by an asterisk "*" and eventually one or several parameters. Examples: *RST *ESE 253 *ESR? RESET, resets the instrument. EVENT STATUS ENABLE, sets the bits of the event status enable registers. EVENT STATUS QUERY, queries the contents of the event status register. Device-specific commands Hierarchy 1110.3339.12 Device-specific commands are of hierarchical structure (see Fig. 5-1). The different levels are represented by combined headers. Headers of the highest level (root level) have only one key word. This key word denotes a complete command system. 5.3 E-5 Structure and Syntax of the Device Messages AMIQ Example: :SYSTem This key word denotes the command system :SYSTem. For commands of lower levels, the complete path has to be specified, starting on the left with the highest level, the individual key words being separated by a colon ":". Example: :SYSTem:BEEPer:STATe ON This command is located on the third level of the SYSTem system. It switches on the beeper (acoustic signal). SYSTem ... COMMunicate BEEPER GPIB SERial CATalog ADDRess BAUD LENGth? Fig. 5-1 ... STATe DELete Example for the tree structure of the SCPI command systems: The SYSTem system Some key words occur on several levels within one command system. Their effect depends on the structure of the command, i. e. on the position in the command header they are inserted in. Example: :MMEMory:DATA:LENGth? This command contains the key word LENGth? in the third command level. The command returns the number of waveform files in the current directory. :MMEMory:DCATalog:LENGth? This command contains the key word LENGth? in the third command level. It returns the number of waveform directories below the virtual root directory. Optional key words Some command systems permit certain key words to be optionally inserted into the command header or omitted. These key words are marked by square brackets in this manual. The full command length must be recognized by the instrument for reasons of compatibility with the SCPI standard. Some commands are considerably shortened by omitting optional key words. Example: :MARKer [:LIST] This command transfers a list of markers to the AMIQ. The following command has the same effect: :MARK Note: 1110.3339.12 An optional key word must not be omitted if its effect is specified more precisely by a numeric suffix. 5.4 E-5 AMIQ Structure and Syntax of the Device Messages The key words feature a long form and a short form. Either the short form or the long form can be entered, other abbreviations are not permissible. Long and short form Example: :STATus:QUEStionable:ENABle 1 :STAT:QUES:ENAB 1 Note: The short form is marked by upper-case letters, the long form corresponds to the complete word. Upper-case and lower-case notation only serves to distinguish the two forms in the manual, the instrument itself does not distinguish upper-case and lower-case letters. Parameters must be separated from the header by a "white space". If several parameters are specified in a command, they are separated by a comma ",". A few queries permit the parameters MINimum, MAXimum and DEFault. For a description of the types of parameter, refer to section, "Parameters". Parameters Example: [:SOURce]:CLOCk frequency[,mode] This command defines the clock rate (frequency) for reading samples from the output memory in various modes. Numeric suffix If a device features several functions or features of the same kind, e.g. outputs, the desired function can be selected by a suffix added to the command. Entries without suffix are interpreted like entries with the suffix 1. Example: :OUTPut:MARKer<2> ON This command activates marker output no. 2. Structure of a Command Line A command line may consist of one or several commands. It is terminated by a , a with EOI or an EOI together with the last data byte. Quick BASIC automatically produces an EOI together with the last data byte. Several commands in a command line must be separated by a semicolon ";". If the next command belongs to a different command system, the semicolon is followed by a colon. Example: CALL IECOUT("MMEM:LOAD RAM,’SINE’;:OUTP:I FIX") This command line contains two commands. The first command belongs to the MMEMory system and loads the SINE.WV waveform. The second command belongs to the OUTPut system and sets the I channel to FIX (Vpp = 1 V into 50 Ω). If the successive commands belong to the same system, having one or several levels in common, the command line can be abbreviated. To this end, the second command after the semicolon starts with the level that lies below the common levels (see also Fig. 5-1). The colon following the semicolon must be omitted in this case. Example: CALL IECOUT("MMEM:MSIS ’C:’;:MMEM:LOAD RAM,’SINE’") This command line, which is shown in its full length, contains two commands separated by a semicolon and a colon. Both commands belong to the MMEMory system, i.e. they have a level in common, so the command line can be abbreviated. In the abbreviated form, the second command starts at the level below MMEM:, i.e. with LOAD. The colon after the semicolon is omitted. The abbreviated command line reads as follows: 1110.3339.12 5.5 E-5 Structure and Syntax of the Device Messages AMIQ CALL IECOUT("MMEM:MSIS ’C:’;LOAD RAM,’SINE’") Each new command line must start with the complete path, however. Example: CALL IECOUT("MMEM:MSIS ’C:’") CALL IECOUT("MMEM:LOAD RAM, ’SINE") Responses to Queries A query is defined for each setting command unless explicitly specified otherwise. It is formed by adding a question mark to the associated setting command. According to SCPI, the responses to queries are partly subject to stricter rules than in standard IEEE 488.2. 1. The requested parameter is transmitted without header. Example: Response: OFF :OUTPut:I[:STATe]? 2. Maximum values, minimum values and all further quantities, which are requested via a special text parameter are returned as numerical values.(not used in AMIQ) 3. Numerical values are output without a unit. Physical quantities are referred to the basic units or to the units set using the Unit command. Example: Response: 1 for 1 V :OUTPut:I:AMPlitude? 4. Boolean values are returned as 0 (for OFF) and 1 (for ON). Example: Response: 1 :SYSTem:BEEPer:STATe? 5. Text (character data) is returned in short form (see also section "Parameters"). Example: OUTPut:FILTer? Response: EXT Parameters Most commands require a parameter to be specified. The parameters must be separated from the header by a "white space". Permissible parameters are numerical values, Boolean parameters, text, character strings and block data. The type of parameter required for the respective command and the permissible range of values are specified in the command description. Numerical values Numerical values can be entered in any form, i.e. with sign, decimal point and exponent. Values exceeding the resolution of the instrument are rounded up or down. The mantissa may comprise up to 255 characters, the exponent must lie inside the value range -32000 to 32000. The exponent is introduced by an "E" or "e". Entry of the exponent alone is not permissible. In the case of physical quantities, the unit can be entered. Permissible unit prefixes are G (giga), MA (mega), MOHM and MHZ are also permissible), K (kilo), M (milli), U (micro) and N (nano). It the unit is missing, the basic unit is used. Example: 1110.3339.12 :OUTPut:I:AMPlitude 0.01 V :OUTPut:I:AMPlitude 1E-4 5.6 is equivalent to E-5 AMIQ Structure and Syntax of the Device Messages Special numerical values The texts MINimum, MAXimum, DEFault, UP and DOWN are interpreted as special numerical values (not used in the AMIQ). In the case of a query, the associated numerical value is provided. Example: MIN/MAX Setting command: Query: :SENSE2:POWer:REFerence MAXimum :SENSE2:POWer:REFerence? Response: 100MW MINimum and MAXimum denote the minimum and maximum value. DEF DEFault denotes a preset value. This value conforms to the default setting, as it is called by the *RST command. UP/DOWN UP, DOWN increases or reduces the numerical value by one step. The step width can be specified via an allocated step command (see chapter 6, "List of Commands") for each parameter which can be set via UP, DOWN. INF/NINF INFinity, Negative INFinity (NINF) represent the numerical values -9.9E37 or 9.9E37, respectively. INF and NINF are only sent as device responses. NAN Not a Number (NAN) represents the value 9.91E37. NAN is only sent as device response. This value is not defined. Possible causes are division of zero by zero, subtraction of infinite from infinite and the representation of missing values. Boolean Parameters Boolean parameters represent two states. The ON state (logically true) is represented by ON or a numerical value unequal to 0. The OFF state (logically untrue) is represented by OFF or the numerical value 0. 0 or 1 is provided in a query. Example: Setting command: :OUTPut:CLOCk ON Query: :OUTPut:CLOCk? Response: 1 Text Text parameters observe the syntactic rules for key words, i.e. they can be entered using a short or long form. Like any parameter, they have to be separated from the header by a white space. In the case of a query, the short form of the text is provided. Example: Strings Strings must always be entered within quotation marks (’ or "). Example: 1110.3339.12 Setting command: :OUTPut:FILTer EXTernal Query: :OUTPut:FILTer? Response: EXT :MMEMory:DELete "winiqsim\foobar" :MMEMory:DELete ’winiqsim\foobar’ 5.7 or E-5 Structure and Syntax of the Device Messages Block data AMIQ Block data is a transmission format which is suitable for the transmission of large amounts of data. A command using a block data parameter has the following structure: Example: :HEADer:HEADer #45168xxxxxxxx The double dagger (ASCII character #) introduces the data block. The next number indicates how many of the following digits describe the length of the data block. In the example the 4 following digits indicate the length to be 5168 bytes. The data bytes follow. During the transmission of these data bytes all delimiters or other control characters are ignored until all bytes are transmitted. Overview of Syntax Elements The following survey offers an overview of the syntax elements. : The colon separates the key words of a command. In a command line the separating semicolon marks the uppermost command level. ; The semicolon separates two commands of a command line. It does not alter the path. , The comma separates several parameters of a command. ? The question mark forms a query. * The asterisk marks a common command. " Quotation marks introduce a string and terminate it. # The double dagger (ASCI character #) introduces block data. A "white space" (ASCII-Code 0 to 9, 11 to 32 decimal, e.g. blank) separates header and parameter. 1110.3339.12 5.8 E-5 AMIQ Instrument Model and Command Processing Instrument Model and Command Processing The instrument model shown in Fig. 5-2 has been made viewed from the standpoint of the servicing of IEC bus commands. The individual components work independently of each other and simultaneously. They communicate by means of so-called "messages". IEC bus Input unit with input buffer Command recognition Data set Status reporting system Instrument hardware IEC bus Fig. 5-2 Output unit with output buffer Instrument model in the case of remote control by means of the IEC bus Input Unit The input unit receives commands character by character from the IEC bus and collects them in the input buffer. The input unit sends a message to the command recognition as soon as the input buffer is full or as soon as it receives a delimiter, , as defined in IEEE 488.2, or the interface message DCL. If the input buffer is full, the IEC bus traffic is stopped and the data received up to then are processed. Subsequently the IEC bus traffic is continued. If, however, the buffer is not yet full when receiving the delimiter, the input unit can already receive the next command during command recognition and execution. The receipt of a DCL clears the input buffer and immediately initiates a message to the command recognition. 1110.3339.12 5.9 E-5 Instrument Model and Command Processing AMIQ Command Recognition The command recognition analyses the data received from the input unit. It proceeds in the order in which it receives the data. Only a DCL is serviced with priority, a GET (Group Execute Trigger), e.g., is only executed after the commands received before. Each recognized command is immediately transmitted to the data set but not executed immediately. Syntactical errors in the command are recognized here and transferred to the status reporting system. The rest of a command line after a syntax error is analyzed further as far as possible and serviced. If the command recognition recognizes a delimiter or a DCL, it requests the data set to set the commands in the instrument hardware as well. Subsequently it is immediately prepared to process commands again. This means for the command servicing that further commands can already be serviced while the hardware is still being set ("overlapping execution"). Data Set and Instrument Hardware The expression "instrument hardware" denotes the part of the instrument fulfilling the actual instrument function - signal generation, measurement etc. The controller is not included. The data set is a detailed software reproduction of the instrument hardware. IEC bus setting commands lead to an alteration in the data set. The data set management enters the new values (e.g. frequency) into the data set, however, only passes them on to the hardware when requested by the command recognition. As this is always only effected at the end of a command line, the order of the setting commands in the command line is not relevant. The data are only checked for their compatibility among each other and with the instrument hardware immediately before they are transmitted to the instrument hardware. If the detection is made that execution is not possible, an "execution error" is signaled to the status reporting system. All alterations of the data set are canceled, the instrument hardware is not reset. Due to the delayed checking and hardware setting, however, impermissible instrument states can be set for a short period of time within one command line without this leading to an error message (example: simultaneous activation of FM and PM). At the end of the command line, however, a permissible instrument state must have been reached again. Before passing on the data to the hardware, the settling bit in the STATus:OPERation register is set (cf. section STATus:OPERation Register). The hardware executes the settings and resets the bit again as soon as the new state has settled. This fact can be used to synchronize command servicing. IEC bus queries induce the data set management to send the desired data to the output unit. Status Reporting System The status reporting system collects information on the instrument state and makes it available to the output unit on request. The exact structure and function are described in section "Status Reporting System" below. 1110.3339.12 5.10 E-5 AMIQ Instrument Model and Command Processing Output Unit The output unit collects the information requested by the controller, which it receives from the data set management. It processes it according to the SCPI rules and makes it available in the output buffer. If the information requested is longer, it is made available "in portions" without this being recognized by the controller. If the instrument is addressed as a talker without the output buffer containing data or awaiting data from the data set management, the output unit sends error message "Query UNTERMINATED" to the status reporting system. No data are sent on the IEC bus, the controller waits until it has reached its time limit. This behavior is specified by SCPI. Command Sequence and Command Synchronization What was said above makes clear that overlapping execution is possible in principle for all commands. Equally, setting commands within one command line are not absolutely serviced in the order in which they have been received. In order to make sure that commands are actually carried out in a certain order, each command must be sent in a separate command line, that is to say, with a separate IBWRT()-call. In order to prevent an overlapping execution of commands, one of commands *OPC, *OPC? or *WAI must be used. All three commands cause a certain action only to be carried out after the hardware has been set and has settled. By a suitable programming, the controller can be forced to wait for the respective action to occur (cf. Table 5-1). Table 5-1 Synchronization with *OPC, *OPC? and *WAI Command Action after the hardware has settled Programming the controller *OPC Setting the operation-complete bit in the ESR - Setting bit 0 in the ESE - Setting bit 5 in the SRE - Waiting for service request (SRQ) *OPC? Writing a "1" into the output buffer Addressing the instrument as a talker *WAI Executing the next command Note: The IEC bus handshake is not stopped Sending the next command An example for command synchronization can be found in chapter 7, "Programming Examples". 1110.3339.12 5.11 E-5 Status Reporting System AMIQ Status Reporting System The status reporting system (cf.Fig. 5-4) stores all information on the present operating state of the instrument, e.g. that the instrument presently carries out an AUTORANGE and on errors which have occurred. This information is stored in the status registers and in the error queue. The status registers and the error queue can be queried via IEC bus. The information is of a hierarchical structure. The register status byte (STB) defined in IEEE 488.2 and its associated mask register service request enable (SRE) form the uppermost level. The STB receives its information from the standard event status register (ESR) which is also defined in IEEE 488.2 with the associated mask register standard event status enable (ESE) and registers STATus:OPERation and STATus:QUEStionable which are defined by SCPI and contain detailed information on the instrument. The IST flag ("Individual STatus") and the parallel poll enable register (PPE) allocated to it are also part of the status reporting system. The IST flag, like the SRQ, combines the entire instrument status in a single bit. The PPE fulfills an analog function for the IST flag as the SRE for the service request. The output buffer contains the messages the instrument returns to the controller. It is not part of the status reporting system but determines the value of the MAV bit in the STB and thus is represented in Fig. 5-4. Structure of an SCPI Status Register Each SCPI register consists of 5 parts which each have a width of 16 bits and have different functions (cf. Fig. 5-3). The individual bits are independent of each other, i.e. each hardware status is assigned a bit number which is valid for all five parts. For example, bit 3 of the STATus:OPERation register is assigned to the hardware status "wait for trigger" in all five parts. Bit 15 (the most significant bit) is set to zero for all parts. Thus the contents of the register parts can be processed by the controller as positive integer. 15 14 13 12 CONDition part 3 2 1 0 15 14 13 12 PTRansition part 3 2 1 0 15 14 13 12 NTRansition part 3 2 1 0 15 14 13 12 EVENt part 3 2 1 0 to higher-order register & & & & & & & & & & & & & & & & + Sum bit 15 14 13 12 Fig. 5-3 ENABle part & = logical AND + = logical OR of all bits 3 2 1 0 The status register model 1110.3339.12 5.12 E-5 AMIQ Status Reporting System CONDition part The CONDition part is directly written into by the hardware or the sum bit of the next lower register. Its contents reflects the current instrument status. This register part can only be read, but not written into or cleared. Its contents is not affected by reading. PTRansition part The Positive-TRansition part acts as an edge detector. When a bit of the CONDition part is changed from 0 to 1, the associated PTR bit decides whether the EVENt bit is set to 1. PTR bit =1: the EVENt bit is set. PTR bit =0: the EVENt bit is not set. This part can be written into and read at will. Its contents is not affected by reading. NTRansition part The Negative-TRansition part also acts as an edge detector. When a bit of the CONDition part is changed from 1 to 0, the associated NTR bit decides whether the EVENt bit is set to 1. NTR bit =1: the EVENt bit is set. NTR bit =0: the EVENt bit is not set. This part can be written into and read at will. Its contents is not affected by reading. With these two edge register parts the user can define which state transition of the condition part (none, 0 to 1, 1 to 0 or both) is stored in the EVENt part. EVENt part The EVENt part indicates whether an event has occurred since the last reading, it is the "memory" of the condition part. It only indicates events passed on by the edge filters. It is permanently updated by the instrument. This part can only be read by the user. Upon reading, its contents is set to zero. In colloquial language, this part is often equated with the entire register. ENABle part The ENABle part determines whether the associated EVENt bit contributes to the sum bit (cf. below). Each bit of the EVENt part is ANDed with the associated ENABle bit (symbol ’&’). The results of all logical operations of this part are passed on to the sum bit via an OR function (symbol ’+’). ENAB bit =0: the associated EVENt bit does not contribute to the sum bit ENAB bit =1: if the associated EVENT bit is "1", the sum bit is set to "1" as well. This part can be written into and read by the user at will. Its contents is not affected by reading. Sum bit As indicated above, the sum bit is obtained from the EVENt and ENABle part for each register. The result is then entered into a bit of the CONDition part of the higher-order register. The instrument automatically generates the sum bit for each register. Thus an event, e.g. a PLL that has not locked, can lead to a service request throughout all levels of the hierarchy. Note: The service request enable register SRE defined in IEEE 488.2 can be taken as ENABle part of the STB if the STB is structured according to SCPI. By analogy, the ESE can be taken as the ENABle part of the ESR. 1110.3339.12 5.13 E-5 Status Reporting System AMIQ Overview of Status Registers SRQ 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 -&-&-&-&- STATus:OPERation register OPER RQS/MSS ESB MAV ERRQ STB SRE 7 6 5 4 3 2 1 0 15 Alwais 0 14 Not used 13 Not used 12 Not used 11 Not used 10 Not used 9 SELFtest 8 Not used 7 Not used 6 Not used 5 Waiting for trigger 4 Not used 3 Not used 2 Not used 1 SETTling 0 CALibrating -&-&-&-&-&-&-&-&-&-&-&-&-&-&-&-&- -&-&-&-&- -&-&-&-&-&-&-&-&ESE 7 Power on 6 Not used 5 Command error 4 Execution error 3 Device dependent error 2 Query error 1 Not used 0 Operation complete ESR STATus:EVENt register -&Responses to queries Error messages PPE Message AVailable IST flag (response to parallel poll) Error queue & = logical AND = logical OR of all bits Fig. 5-4 The Status registers 1110.3339.12 5.14 E-5 AMIQ Status Reporting System Description of the Status Registers Status Byte (STB) and Service Request Enable Register (SRE) The STB is already defined in IEEE 488.2. It provides a rough overview of the instrument status by collecting the pieces of information of the lower registers. It can thus be compared with the CONDition part of an SCPI register and assumes the highest level within the SCPI hierarchy. A special feature is that bit 6 acts as the sum bit of the remaining bits of the status byte. The STATUS BYTE is read out using the command "*STB?" or a serial poll. The STB is linked to the SRE. The latter corresponds to the ENABle part of the SCPI registers in its function. Each bit of the STB is assigned a bit in the SRE. Bit 6 of the SRE is ignored. If a bit is set in the SRE and the associated bit in the STB changes from 0 to 1, a Service Request (SRQ) is generated on the IEC bus, which triggers an interrupt in the controller if this is appropriately configured and can be further processed there. The SRE can be set using command "*SRE" and read using "*SRE?". Table 5-2 Meaning of the bits used in the status byte Bit no. Meaning 2 Error Queue not empty The bit is set when an entry is made in the error queue. If this bit is enabled by the SRE, each entry of the error queue generates a Service Request. Thus an error can be recognized and specified in greater detail by polling the error queue. The poll provides an informative error message. This procedure is to be recommended since it considerably reduces the problems involved with IEC bus control. 3 vacant 4 MAV-Bit (Message AVailable) The bit is set if a message is available in the output buffer which can be read. This bit can be used to enable data to be automatically read from the instrument to the controller (cf. chapter 7, "Programming Examples"). 5 ESB bit Sum bit of the event status register. It is set if one of the bits in the event status register is set and enabled in the event status enable register. Setting of this bit indicates a serious error which can be specified in more detail by polling the event status register. 6 MSS-Bit (Master Status Summary bit) The bit is set if the instrument triggers a service request. This is the case if one of the other bits of this register is set together with its mask bit in the service request enable register SRE. 7 OPERation status register sum bit The bit is set if an EVENt bit is set in the OPERation status register and the associated ENABle bit is set to 1. A set bit indicates that the instrument is just performing an action. The type of action can be queried by polling the OPERation status register. 1110.3339.12 5.15 E-5 Status Reporting System AMIQ IST Flag and Parallel Poll Enable Register (PPE) By analogy with the SRQ, the IST flag combines the entire status information in a single bit. It can be queried by means of a parallel poll (cf. section "Parallel Poll") or using the command "*IST?". The parallel poll enable register (PPE) determines which bits of the STB contribute to the IST flag. The bits of the STB are ANDed with the corresponding bits of the PPE, with bit 6 being used as well in contrast to the SRE. The IST flag results from the ORing of all results. The PPE can be set using commands "*PRE" and read using command "*PRE?". Event Status Register (ESR) and Event Status Enable Register (ESE) The ESR is already defined in IEEE 488.2. It can be compared with the EVENt part of an SCPI register. The event status register can be read out using command "*ESR?". The ESE is the associated ENABle part. It can be set using the command "*ESE" and read using the command "*ESE?". Table 5-3 Meaning of the bits used in the event status register Bit No. Meaning 0 Operation Complete This bit is set on receipt of the command *OPC exactly when all previous commands have been executed. 1 Request Control This bit is not used in the AMIQ. 2 Query Error This bit is set if either the controller wants to read data from the instrument without having sent a query, or if it does not fetch requested data and sends new instructions to the instrument instead. The cause is often a query which is faulty and hence cannot be executed. 3 Device-dependent Error This bit is set if a device-dependent error occurs. An error message with a number between -300 and -399 or a positive error number, which denotes the error in greater detail, is entered into the error queue (cf. chapter 9, "Error Messages"). 4 Execution Error This bit is set if a received command is syntactically correct but cannot be performed for other reasons. An error message with a number between -200 and -300, which denotes the error in greater detail, is entered into the error queue (cf. chapter 9, "Error Messages"). 5 Command Error This bit is set if a command which is undefined or syntactically incorrect is received. An error message with a number between -100 and -200, which denotes the error in greater detail, is entered into the error queue (cf. chapter 9, "Error Messages"). 6 User Request This bit is not used in the AMIQ. 7 Power On (supply voltage on) This bit is set on switching on the instrument. 1110.3339.12 5.16 E-5 AMIQ Status Reporting System STATus:OPERation Register In the CONDition part, this register contains information on which actions the instrument is being executing or, in the EVENt part, information on which actions the instrument has executed since the last reading. It can be read using one of the commands "STATus:OPERation:CONDition?" or "STATus:OPERation [:EVENt]?".. Table 5-4 Meaning of the bits used in the STATus:OPERation register Bit-No. Meaning 0 CALibrating This bit is set as long as an internal adjustment routine is executed. 1 SETTing This bit is set as long as a new hardware status is settling after a setting command. 5 Waiting for TRIGGER This bit is set as long as the instrument is waiting for a trigger event. 9 Selftest This bit is set while the instrument executes the command *TST? or one of the commands DIAG:SELF:xxx? STATus:QUEStionable Register This register contains information on questionable instrument states. They can occur, e.g. if the instrument is operated outside its specified range. It can be queried using one of the commands ":STATus :QUEStionable:CONDition?" or ":STATus:QUEStionable[:EVENt]?". Table 5-5 Bit-No. Meaning of the bits used in the STATus:QUEStionable register Meaning At present, no bits of this register are used in the AMIQ. 1110.3339.12 5.17 E-5 Status Reporting System AMIQ Application of the Status Reporting System In order to effectively use the status reporting system, the information contained there must be transmitted to the controller to be further processed. There are several methods which are outlined in the following. For detailed program examples, see chapter 7, "Programming Examples". Service Request, Making Use of the Hierarchy Structure Under certain circumstances, the instrument can send a service request (SRQ) to the controller. Usually this service request initiates an interrupt at the controller, to which the control program can react appropriately. As evident from Fig. 5-4, an SRQ is always initiated if one or several of bits 2, 3, 4, 5 or 7 of the status byte are set and enabled in the SRE. Each of these bits combines the information of a further register, the error queue or the output buffer. The corresponding setting of the ENABle parts of the status registers can achieve that arbitrary bits in an arbitrary status register initiate an SRQ. In order use the possibilities of the service request effectively, all bits should be set to "1" in the enable registers SRE and ESE. Examples (cf.Fig. 5-3, section Overview of Status Registers and chapter 7, "Programming examples"): Use command "*OPC" to generate an SRQ: ½ Set bit 0 in the ESE (Operation Complete) ½ Set bit 5 in the SRE (ESB) After its settings have been completed, the instrument generates an SRQ. Indication of the end of a measurement by means of an SRQ with the controller: ½ Set bit 7 in the SRE (sum bit of the STATus:OPERation register) ½ Set bit 4 (measuring) in the STATus:OPERation:ENABle. ½ Set bit 4 in the STATus:OPERation:NTRansition so as to make sure that the transition of measuring bit 4 from 1 to 0 (end of measurement) is recorded in the EVENt part. After a sweep has been completed, the instrument generates an SRQ. The SRQ is the only possibility for the instrument to become active on its own. Each controller program should set the instrument such that a service request is initiated in the case of malfunction. The program should react appropriately to the service request. A detailed example for a service request routine can be found in chapter 7, "Programming examples". 1110.3339.12 5.18 E-5 AMIQ Status Reporting System Serial Poll In a serial poll, just as upon the command "*STB", the status byte of an instrument is queried. However, the query is made via interface messages and is thus clearly faster. The serial-poll method has already been defined in IEEE 488.1 and used to be the only standard possibility for different instruments to poll the status byte. The method also works for instruments which do not adhere to SCPI or IEEE 488.2. The quick-BASIC command for executing a serial poll is "IBRSP()". The serial poll is mainly used to obtain a fast overview of the state of several instruments connected to the IEC bus. Parallel Poll In a parallel poll, up to eight instruments are simultaneously requested by the controller by means of a single command to transmit 1 bit of information each on the data lines, i.e., to set the data line allocated to each instrument to a logic "0" or "1". By analogy to the SRE register which determines under which conditions an SRQ is generated, there is a parallel poll enable register (PPE) which is ANDed with the STB bit by bit, considering bit 6 – AND as well. The results are ORed, the result is then sent (possibly inverted) as a response to the parallel poll of the controller. The result can also be queried without parallel poll by means of the command "*IST". The instrument first has to be set for the parallel poll using the quick-BASIC command "IBPPC()". This command allocates a data line to the instrument and determines whether the response is to be inverted. The parallel poll itself is executed using "IBRPP()". The parallel-poll method is mainly used in order to quickly find out after an SRQ which instrument has sent the service request if there are many instruments connected to the IEC bus. To this effect, SRE and PPE must be set to the same value. A detailed example for a parallel poll can be found in chapter 7, "Programming Examples". Query by Means of Commands Each part of any status register can be read by means of queries. The individual commands are listed in the detailed description of the registers in section Overview of Status Registers. What is returned is always a number which represents the bit pattern of the register queried. Evaluating this number is effected by the controller program. Queries are usually used after an SRQ in order to obtain more detailed information on the cause of the SRQ. Error Queue Query Each error state in the instrument leads to an entry in the error queue. The entries of the error queue are detailed plain-text error messages which can be looked at in the ERROR menu via manual control or queried via the IEC bus using command "SYSTem:ERRor?". Each call of "SYSTem:ERRor?" provides one entry from the error queue. If no error messages are stored there any more, the instrument responds with 0, "No error" The error queue should be queried after every SRQ in the controller program as the entries describe the cause of an error more precisely than the status registers. Especially in the test phase of a controller program the error queue should be queried regularly since faulty commands from the controller to the instrument are recorded there as well. 1110.3339.12 5.19 E-5 Status Reporting System AMIQ Reset Values of the Status Reporting Systems Table5-6 summarizes the different commands and events causing the status reporting system to be reset. None of the commands, except *RST and SYSTem:PRESet influences the functional instrument settings. In particular, DCL does not change the instrument settings. Table5-6 Resetting instrument functions Event Switching on supply voltage DCL,SDC Power-On-StatusClear Effect 0 (Device Clear, Selected Device Clear) *RST or SYSTem:PRESet STATus:PRESet *CLS 1 Clear STB,ESR yes yes Clear SRE,ESE yes Clear PPE yes Clear EVENt parts of the registers yes yes Clear ENABle parts of all OPERation-and QUESTionable registers, Fill ENABle parts of all other registers with "1". yes yes Fill PTRansition parts with „1" Clear NTRansition parts yes yes Clear error queue yes yes yes Clear output buffer yes yes yes 1) 1) 1) Clear command processing and input buffer yes yes yes 1) Every command being the first in a command line, i.e. immediately following a clears the output buffer. 1110.3339.12 5.20 E-5 AMIQ Hardware Interfaces Hardware Interfaces IEC/IEEE Bus Interface The standard instrument is equipped with an IEC/IEEE-bus connection. The IEEE 488 interface connector is located on the rear panel of the instrument. A controller for remote control can be connected via the IEEE 488 interface using a shielded cable. Characteristics of the Interface é 8-bit parallel data transfer, é bidirectional data transfer, é three line handshake, é high data transfer rate of max. 350 kByte/s, é up to 15 devices can be connected, é maximal length of the connecting cables 15 m (single connection 2 m), é wired OR if several instruments are connected in parallel. ATN shield IFC SRQ NRFD NDAC EOI DAV DIO3 DIO4 12 24 logic GND Fig. 5-5 DIO2 1 13 GND(10) GND(11) DIO1 GND(8) GND(9) GND(6) GND(7) REN DIO8 DIO7 DIO6 DIO5 Pin Assigment of the IEC-bus interface Bus Lines 1. Data bus with 8 lines DIO 1 to DIO 8. The transmission is bit-parallel and byte-serial in the ASCII/ISO code. DIO1 is the least significant bit, DIO8 the most significant bit. 1110.3339.12 5.21 E-5 Hardware Interfaces AMIQ 2. Control bus with 5 lines IFC (Interface Clear), active LOW resets the interfaces of the instruments connected to the default setting. ATN (Attention), active LOW signals the transmission of interface messages inactive HIGH signals the transmission of device messages. SRQ (Service Request), active LOW enables the connected device to send a service request to the controller. REN (Remote Enable), active LOW permits switchover to remote control. EOI (End or Identify), has two functions in connection with ATN: ATN=HIGH active LOW marks the end of data transmission. ATN=LOW active LOW triggers a parallel poll. 3. Handshake bus with three lines DAV (Data Valid), active LOW signals a valid data byte on the data bus. NRFD (Not Ready For Data), active LOW signals that one of the connected devices is not ready for data transfer. NDAC (Not Data Accepted), active LOW signals that the instrument connected is accepting the data on the data bus. Interface Functions Instruments which can be controlled via IEC bus can be equipped with different interface functions. Table 5-7 Interface functions 1110.3339.12 Control character Interface function SH1 Handshake source function (source handshake) AH1 Handshake drain function (acceptor handshake) L4 Listener function T6 Talker function, ability to respond to serial poll SR1 Service request function PP1 Parallel poll function RL1 Remote/Local switchover function DC1 Reset function (Device Clear) DT1 Trigger function (Device Trigger) 5.22 E-5 AMIQ Hardware Interfaces Interface Messages Interface messages are transmitted to the instrument on the data lines, with the attention line being active (LOW). They serve to communicate between controller and instrument. Universal Commands Universal commands are encoded in the range 10 through 1F hex. They are effective for all instruments connected to the bus without pervious addressing. Table 5-8 Universal Commands Command QuickBASIC command Effect on the instrument DCL (Device Clear) IBCMD (controller%, CHR$(20)) Aborts processing of the commands just received and sets the command processing software to a defined initial state. Does not change the instrument setting. IFC (Interface Clear) IBSIC (controller%) Resets the interfaces to the default setting. LLO (Local Lockout) IBCMD (controller%, CHR$(17)) The LOC/IEC ADDR key is disabled. SPE (Serial Poll Enable) IBCMD (controller%, CHR$(24)) Ready for serial poll. SPD (Serial Poll Disable) IBCMD (controller%, CHR$(25)) End of serial poll. PPU (Parallel Poll Unconfigure) IBCMD (controller%, CHR$(21)) End of the parallel-poll state. Addressed Commands Addressed commands are encoded in the range 00 through 0F hex. They are only effective for instruments addressed as listeners. Table 5-9 Addressed Commands Command QuickBASIC command Effect on the instrument SDC (Selected Device Clear) IBCLR (device%) Aborts processing of the commands just received and sets the command processing software to a defined initial state. Does not change the instrument setting. GET (Group Execute Trigger) IBTRG (device%) Triggers a previously active device function. The effect of the command is the same as with that of a pulse at the external trigger signal input. GTL (Go to Local) IBLOC (device%) Transition to the "Local" state (manual control). PPC (Parallel Poll Configure) IBPPC (device%, data%) Configure instrument for parallel poll. The QuickBASIC command additionally executes PPE / PPD. 1110.3339.12 5.23 E-5 RS-232-C Interface AMIQ RS-232-C Interface The standard instrument is equipped with an RS-232-C interface. The 9-pin connector is located on the rear panel. A controller can be connected via this interface for remote control. Interface characteristics é Serial data transmission in asynchronous mode, é Bidirectional data transmission via two separate lines, é Transmission rate selectable from 300 to 115200 baud, é Logic 0 signal from +3 V to +15 V, é Logic 1 signal from -15 V to -3 V, é An external instrument (controller) can be connected, é Hardware handshake RTS/CTS set. RxD DTR TxD 5 1 9 6 RTS DSR CTS Fig. 5-6 Pin assigment of the RS-232-C interface Signal lines RxD (Receive Data), Input; data line for transmitting from remote station to local terminal. TxD (Transmit Data), Output; data line for transmitting from local terminal to remote station. DTR (Data Terminal Ready), Output (log. ’0’ = active); with DTR, the instrument indicates that it is ready to receive data. GND (Ground), Interface ground, connected to instrument ground. DSR (Data set ready), Input (log. ’0’ = active); DSR indicates to the instrument that the remote station is ready to receive data. RTS (Request to send), Output (log. ’0’ = active); with RTS, the instrument indicates that it is ready to receive data. The RTS line controls whether the instrument is ready to receive data or not. CTS (Clear to send), Input (log. ’0’ = active); CTS tells the instrument that the remote station is ready to receive data. 1110.3339.12 5.24 E-5 AMIQ RS-232-C Interface Transmission parameters In order to ensure error-free and correct data transmission, the parameters of the instrument and the controller must be set identically. Transmission rate (baud rate) Baud rates ranging from 1200 to 115200 can be set in the instrument: see chapter 6, :SYSTem:COMMunicate:SERial:Baud. Data bits Data transmission is in 8-bit ASCII code. The first bit transmitted is the LSB (Least Significant Bit). Start bit Each data byte begins with a start bit. The falling edge of the start bit indicates the beginning of the data byte. Parity bit No parity bit is used. Stop bit The transmission of a data byte is terminated by a stop bit. Example: Transmission of character A (41 hex) in the 8-bit ASCII code. 01 02 03 Bit 01 = Start bit Bitduration= 1/baud rate 04 05 06 Bit 02...09 = Data bits 07 08 09 10 Bit 10 = Stop bit Interface functions For interface control, some control characters from the ASCII code range of 0 to 20 hex are predefined and can be transmitted via the interface (see Table A-4). Table 5-10 Control strings or control characters of the RS-232-C interface Control Character Function Break (at least 1 character only log 0) Reset of instrument Waiting time until output of new command: 100 ms 0Dhex, 0Ahex Terminator of commands , Switchover between local and remote 1110.3339.12 5.25 E-5 RS-232-C Interface AMIQ Handshake Hardware handshake In case of a hardware handshake, the instrument signals that it is ready for reception via line DTR and RTS. A logic ’0’ means "ready" and a ’1’ means "not ready". The CTS or DSR lines (see signal lines) tell the instrument whether the controller is ready for reception or not. The transmitter of the instrument is switched on by a ’0’ and switched off by a ’1’. The RTS line remains active as long as the serial interface is active. The DTR line controls whether the instrument is ready for reception or not. AMIQ Controller / PC 1 1 DSR RxD RTS TxD CTS DTR 6 DSR 6 2 2 3 3 TxD 8 CTS 8 4 4 9 9 GND RxD 7 RTS 7 5 5 DSUB connector, 9 poles / female DTR GND DSUB connector, 9 poles / female Connection between instrument and controller (Null-modem cable) AMIQ Controller / PC 1 14 1 DSR RxD RTS TxD CTS DTR 15 2 RxD 3 7 16 3 RTS 4 8 17 4 CTS 5 9 GND TxD 2 6 The connection of the instrument to a controller is made with a so-called nullmodem cable. Here, the data, control and signalling lines must be crossed. The wiring diagram on the left applies to a controller with a 9-pin or 25-pin configuration. 18 5 DSR 6 19 7 DSUB connector, 9 poles / female GND 20 DTR 8 21 9 22 10 23 11 24 12 25 13 DSUB connector, 25 poles / female Fig. 5-7 Null-modem connection scheme 1110.3339.12 5.26 E-5 AMIQ Notation 6 Remote Control – Commands and Data Formats In the following sections, all remote control commands of the AMIQ are first listed in tables and then described in detail, separated according to the command systems. The notation largely corresponds to the one of the SCPI standards. All commands can be used for control via IEC/IEEE bus, the serial interface and via the batch files on floppies and the hard disk (see :PROGram subsystem). In the detailed description always the shortest possible command line is given as an example for all commands, except common commands. The value specified for each command is the value set after an *RST. No values are required for queries and commands triggering an action (eg *CLS). Notation Table of commands Command: The command column provides an overview of the commands and their hierarchical arrangement. Parameters: The parameters column indicates the requested parameters together with their specified range. Remark: In the remark column, all commands are indicated − which do not have a query form, − which have only one query form , − which are implemented only in conjunction with a certain option of the instrument. Upper/lower case characters Special characters | Upper /lower case characters serve to mark the long or short form of the keywords of a command. The shortform consists of upper case characters, the long form comprises upper/lower case characters. Only these two forms are permissible. The instrument itself does not distinguish between upper and lower case characters. A selection of keywords with identical effect exists for several commands. These keywords are indicated in the same line, they are separated by a vertical stroke. Only one of these keywords has to be specified in the header of the command. The effect of the command is independent of which of the keywords is specified. :MMEMory :CD | CDIRectory first level second level A vertical stroke between the parameters marks alternative options in the sense of "or". The effect of the command is different, depending on which parameter is entered. Example: Selection of the parameters for the command :TRIGger:SLOPe RISing | HIGH 1110.3339.12 6.1 E-7 Notation AMIQ [ ] Key words in square brackets can be omitted when composing the header (see 78chapter 5, section "Structure of a Command" – Optional Keywords). The full command length must be accepted by the instrument for reasons of compatibility with the SCPI standards. Parameters in square brackets are optional and can be omitted. This sign marks the numeric suffix, which identifies marker outputs, for instance. Angle brackets mark a character data parameter that has to be specified within quotation marks (""). For instance, *RCL may become *RCL "sine". 1110.3339.12 6.2 E-7 AMIQ Common Commands Common Commands The common commands are taken from the IEEE 488.2 (IEC 625.2) standard (except for those marked "not IEEE 488.2" which are device-specific extensions). They have the same effect on all devices. The headers of these commands consist of an asterisk * followed by three letters. Many common commands refer to the status reporting system which is described in detail in chapter 5, under "Status Reporting System". Table 6-1 Common commands Command Parameters Remark *CLS No query *DCL Not IEEE 488.2 *ESE 0 to 255 *ESR? Query only *GTL Not IEEE 488.2 *IDN? Query only *IST? Query only *OPC *OPT? Query only *RCL *RST *SAV *SRE 0 to 255 *STB? Query only *TRG *TST? Query only *WAI *CLS CLEAR STATUS sets the status byte (STB), the Standard Event Register (ESR) and the EVENt-part of the QUEStionable and the OPERation register to zero. The command does not alter the mask and transition parts of the status registers. It clears the output buffer. Example: 1110.3339.12 *CLS 6.3 E-7 Common Commands AMIQ *DCL DEVICE CLEAR resets the remote control logic of the device to a defined default state. The command is equivalent to the line message Device Clear but can also be used via the serial interface. Device settings (loaded waveforms, output level, etc) are not changed. Example: *DCL *ESE 0 to 255 EVENT STATUS ENABLE sets the Event Status Enable register to the value indicated. The query *ESE? returns the contents of the event status enable register in decimal representation. Example: *RST value: 0 *ESE 255 *ESR? EVENT STATUS REGISTER returns the contents of the Event Status Register in decimal representation and then sets the register to zero. Example: *ESR? *GTL GO TO LOCAL pseudo command. The GTL line message via the IEC/IEEE bus has the same function. After this command all remote control channels are active. The channel on which the next command arrives will be used. This command is mainly intended for the serial interface. The interface message "gtl" should be used instead on the IEC/IEEE bus because, when the command *GTL is sent, the IEC/IEEE-bus talker function of the host will not notice that the device has changed to the local mode and requires to be newly addressed. Example: *GTL *IDN? IDENTIFICATION QUERY – The response of AMIQ is Rohde & Schwarz, AMIQ, ssssss/sss, x.yy, where ssssss/sss is the serial number and x.yy the software version. Example: *IDN? Response eg: "Rohde&Schwarz,AMIQ,123456/789,3.0" "Rohde&Schwarz,AMIQ02,123456/789,3.0" "Rohde&Schwarz,AMIQ03,123456/789,3.0" "Rohde&Schwarz,AMIQ04,123456/789,3.0" for AMIQ model 02 for AMIQ model 02 with 03 board for AMIQ model 03 for AMIQ model 04 *IST? INDIVIDUAL STATUS QUERY returns the contents of the IST flag in decimal form (0 or 1). The IST flag can also be queried by means of a Parallel Poll. Example: 1110.3339.12 *IST? 6.4 E-7 AMIQ Common Commands *OPC or *OPC? OPERATION COMPLETE sets bit 0 in the Event Status Register when all preceding commands have been executed. This bit can be used to initiate a Service Request, if bit 5 in the Status Enable Register is set. Advantage of *OPC over *OPC?: The program can perform other tasks while waiting for an SRQ after an "operation complete" bit has been set in the Event Status Register. The query OPC? returns a "1" as soon as all preceding commands have been executed. Thus the controller and the device can easily be synchronized. The "1" is insignificant however – the procedure is so that, for example, the "ibrd" instruction (function from National Instruments for reading data from the IEC/IEEE bus) stops program execution until a "1" is placed in the output buffer. Sending an *OPC? query is therefore not a suitable procedure for waiting for a "1" in a program loop. This can be done with *OPC. Example: *OPC? *OPT? OPTION IDENTIFICATION QUERY returns a list of installed options separated by commas. A zero in the list indicates that an option is not installed. The following options are available at present: − AMIQ-B1: BER Measurement − AMIQB19: Rear I/Q Outputs − AMIQ-B2: Differential I/Q Outputs − AMIQK11: IS-95 CDMA − AMIQ-B3: Digital I/Q Output − AMIQK12: CDMA 2000 (from WinIQSIM Version 3.20) − AMIQK13: not assigned − AMIQK14: Digital Standard TD-SCDMA (from WinIQSIM Version 3.50) − AMIQK15: OFDM Signal Generation (from WinIQSIM Version 3.40) − AMIQK16: Digital Standard 802.11b Wireless LAN The query *OPT? returns the designations of all options installed in the order given above. Options not installed are designated "0". In the example below, the zeros indicate that options AMIQB19, AMIQK13, AMIQK14 and AMIQK16 are not installed. Example: *OPT? Response: AMIQB1,0,AMIQB2,AMIQK11,AMIQB3,AMIQK12,0,0,AMIQK15,0 *RCL RECALL recalls the device status file (files with extension .CFG) from drive C: and sets status saved with *SAV under . The extension .CFG may be omitted. It is not specify any drive names and paths; the default drive set via MMEM:MSIS is does not exist, an error message is generated. No distinction is made between lower case letters for the parameter . the device allowed to ignored. If upper and A device status can be loaded from or saved to floppy disk and thus transferred to another device. See SYSTem:STATe:COPY