Microhard Systems 00P3 900 MHz Spread Spectrum Module User Manual CompactRFMAN
Microhard Systems Inc 900 MHz Spread Spectrum Module CompactRFMAN
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Operating Manual And Professional Installation Guide TM CompactRF OEM Spread Spectrum Transceiver Revision 1.00, Sept 15, 2000 Microhard Systems Inc. #110, 1144 - 29th Ave. N.E. Calgary, Alberta T2E 7P1 Phone: (403) 248-0028 Fax: (403) 248-2762 www.microhardcorp.com TM CompactRF 900 MHz OEM Spread Spectrum Transceiver This manual contains information of proprietary interest to Microhard Systems Inc. It has been supplied in confidence to purchasers and users of the CompactRF, and by accepting this material the recipient agrees that the contents will not be copied or reproduced, in whole or in part, without prior written consent of Microhard Systems Inc. Microhard Systems Inc. has made every effort to assure that this document is accurate and complete. However, the company reserves the right to make changes or enhancements to the manual and/or the product described herein at any time and without notice. Furthermore, Microhard Systems Inc. assumes no liability resulting from any omissions in this document, or out of the application or use of the device described herein. Microhard Systems’ products are appropriate for home, office, or industrial use, but are not authorized for utilization in applications where failure could result in damage to property or human injury or loss of life. The electronic equipment described in this manual generates, uses, and radiates radio frequency energy. Operation of this equipment in a residential area may cause radio interference, in which case the user, at his own expense, will be required to take whatever measures necessary to correct the interference. FCC Declaration of Conformity This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received including interference that may caused undesired operation. Microhard Systems Inc.’s products are warranted against all failures which occur as a result of defective material or workmanship within 12 months of purchase by the user. This warranty does not extend to products that, in the opinion of Microhard Systems Inc., have been subject to misuse, accidents, lightning strikes, improper installation or application, nor shall it extend to units which have, in Microhard Systems Inc.’s opinion, been opened, tampered with or repaired by an unauthorized facility. Microhard Systems Inc. Leaders in Wireless Telecom th #110, 1144 - 29 Ave. N.E. Calgary, Alberta T2E 7P1 Phone: (403) 248-0028 Fax: (403) 248-2762 www.microhardcorp.com ii © 2000 by Microhard Systems Inc., All Rights Reserved. HyperTerminal is copyrighted by Hilgraeve Inc, and developed for Microsoft. Microsoft and Windows are registered trademarks of Microsoft Corporation. pcANYWHERE and Symantec are registered trademarks of Symantec Corp. All other products mentioned in this document are trademarks or registered trademarks of their respective holders. Manual Revision 1.00, Sept 15, 2000. CompactRF TM Operating Manual Contents 1. 2. 3. 4. 5. A. B. C. ..... F. G. H. I. iii Introduction 1.0 Product Overview .............................................................................................................................................................................. 1 1.1 Features.............................................................................................................................................................................................. 1 1.2 About this Manual ............................................................................................................................................................................. 2 1.3 Unpacking and Inspection ................................................................................................................................................................. 3 Electrical/Physical 2.0 Functional Block Diagram ................................................................................................................................................................. 5 2.1 Pinout................................................................................................................................................................................................. 6 2.2 DC Characteristics ............................................................................................................................................................................. 8 2.3 AC Characteristics .............................................................................................................................................................................. 9 Mode of Operation 3.1 Data Mode ....................................................................................................................................................................................... 11 3.2 Command Mode .............................................................................................................................................................................. 12 3.2.1 Menu Interface......................................................................................................................................................................... 13 3.2.2 AT Command Interface........................................................................................................................................................... 13 3.3 Switching Between Command and Data Modes .............................................................................................................................. 14 3.3.1 Switching Between AT Command Interface and Data Mode................................................................................................... 14 3.3.2 Switching Menu Interface and Data Mode.............................................................................................................................. 15 3.4 Sleep Mode ...................................................................................................................................................................................... 15 Configuration 4.1 Quick Start Approach ...................................................................................................................................................................... 17 4.2 AT Commands................................................................................................................................................................................. 18 4.3 AT Registers .................................................................................................................................................................................... 21 4.4 Configuration Settings ..................................................................................................................................................................... 22 S Register 101 - Operating Mode..................................................................................................................................................... 23 S Register 102 - Serial Baud Rate.................................................................................................................................................... 25 S Register 104 - Network Address ................................................................................................................................................... 26 S Register 105 - Unit Address.......................................................................................................................................................... 26 S Registers 106 and 206 - Primary and Secondary Hopping Patterns.............................................................................................. 26 S Register 107 - Encryption Key...................................................................................................................................................... 28 S Register 108 - Output Power Level............................................................................................................................................... 28 S Register 109 - Hopping Interval.................................................................................................................................................... 29 S Register 110 - Data Format............................................................................................................................................................ 29 S Registers 111 and 112 - Packet Minimum and Maximum Size..................................................................................................... 30 S Register 116 - Packet Character Timeout ...................................................................................................................................... 30 S Registers 113 and 213 - Packet Retransmission/Packet Retry Limit ............................................................................................. 31 S Register 115 - Packet Repeat Interval........................................................................................................................................... 31 S Register 122 - Link Handshaking .................................................................................................................................................. 32 S Register 117 - Modbus Mode ........................................................................................................................................................ 32 S Register 120 and 121- RTS/DCD Framing/Timeout ..................................................................................................................... 33 S Register 123 - RSSI Reading ......................................................................................................................................................... 33 Installation 5.1 Estimating the Gain Margin............................................................................................................................................................. 35 5.2 Antennas and Cabling...................................................................................................................................................................... 37 5.2.1 Internal Cabling ....................................................................................................................................................................... 37 5.2.2 Installing External Cables, Antennas and Lightning Arrestors................................................................................................ 38 Modem Command Summary ...................................................................................................................................................................... 41 Serial Interface ............................................................................................................................................................................................ 43 Factory Default Settings.............................................................................................................................................................................. 45 Performance Tables...................................................................................................................................................................................... 47 .............................................................................................................................................................................. Technical Specifications ............................................................................................................................................................................. 51 Development Board Schematics ................................................................................................................................................................. 53 Mechanical Drawing................................................................................................................................................................................... 59 Glossary ...................................................................................................................................................................................................... 61 CompactRF TM Operating Manual iv CompactRF TM Operating Manual 1. Introduction 1.0 Product Overview The CompactRFTM is a high-performance embedded wireless data transceiver. Operating in the 902-928 MHz ISM band, this frequencyhopping spread-spectrum module is capable of providing reliable wireless data transfer between almost any type of equipment which uses an asynchronous serial interface. The small-size and low operating current of this module make it ideal for mobile and battery powered applications. Typical uses for this module include: Automated Meter Reading (AMR); Vending Machines; Point of Sale Devices; Fleet Management; Telemetry; Remote Camera/Robot Control; Security Systems; and, Display Signs. While a pair of CompactRFTM modules can link two terminal devices (“pointto-point” operation), multiple modules can be used together to create a network of various topologies, including “point-to-multipoint” and “repeater” operation. Multiple independent networks can operate concurrently, so it is possible for unrelated communications to take place in the same or a nearby area without sacrificing privacy or reliability. 1.1 Features Key features of the CompactRFTM include: n transmission within a public, license-exempt band of the radio spectrum1 – this means that it can be used without access fees (such as those incurred by cellular airtime); n a serial I/O data port with handshaking and hardware flow control, allowing the CompactRFTM to interface directly to any equipment with an asynchronous serial interface. CompactRF TM 902-928 MHz, which is license-free within North America; may need to be factory-configured differently for some countries. Operating Manual: Chapter 1 Introduction. n 30 sets of user-selectable pseudo-random hopping patterns, intelligently designed to offer the possibility of separately operating multiple networks while providing security, reliability and high tolerance to interference; n encryption key with 65536 user-selectable values to maximize security and privacy of communications; n built-in CRC-16 error detection and auto re-transmit to provide 100% accuracy and reliability of data; n ease of installation and use – the CompactRFTM gives the user the choice of a menu interface, or a subset of standard AT style commands, very similar to those used by traditional telephone line modems. While the typical application for the CompactRFTM is to provide a short- to mid-range wireless communications link between DTEs, it can be adapted to almost any situation where an asynchronous serial interface is used and data intercommunication is required. 1.2 About this Manual This manual has been provided as a guide and reference for installing and using CompactRFTM wireless transceivers. The manual contains instructions, suggestions, and information which will help you set up and achieve optimal performance from your equipment using the CompactRFTM. It is assumed that users of the CompactRFTM have either system integration or system design experience. Chapter 2 details the physical/electrical characteristics of the module. Chapter 3 gives an overview of the modes of operation. Chapter 4 describes the AT command register/menu setup and configuration. Chapter 5 is an installation/deployment guide. The Appendices, including the Glossary of Terms, are provided as informational references which you may find useful throughout the use of this manual as well as during the operation of the product. Throughout the manual, you will encounter not only illustrations that further elaborate on the accompanying text, but also several symbols which you should be attentive to: Caution or Warning: Usually advises against some action which could result in undesired or detrimental consequences. Point to Remember: Highlights a key feature, point, or step which is worth noting, Keeping these in mind will make using the CompactRF more useful or easier to use. Tip: An idea or suggestion is provided to improve efficiency or to make something more useful. With that in mind, enjoy extending the boundaries of your communications with the CompactRFTM. CompactRF TM Operating Manual: Chapter 1 Introduction 1.3 Unpacking and Inspection The following items should be found in the shipping carton. Inspect the contents for any shipping damage. Report damages or shortages to the distributor from which the unit was purchased. Keep all packing materials in the event that transportation is required in the future. Package contents for the CompactRF development kit (normal distribution): CompactRF Operating Manual (this document) 12V Wall Adapter DB9 Straight-through Serial Cable Rubber Duck Antenna CompactRF TM Operating Manual: Chapter 1 Introduction. TM TM CompactRF Wireless Module Development Board 4 CompactRF TM Operating Manual: Chapter 1 Introduction 2. Electrical/Physical 2.0 Functional Block Diagram DVcc ARSSI AVcc Mixer LNA Antenna Switch IF Demod GND - + Frequency Synthesizer Comparator Mixer PA GAIN \Config \Reset \Sleep RSSI1-3 SYNC RXMODE TXMODE uC A/D SRAM EEPROM 8 bit data bus TxD RTS DTR CompactRF TM Operating Manual: Chapter 2 Electrical/Physical UART (DCE) RxD CTS DSR DCD 2.1 Pinout Figure 1 provides a top-view pinout drawing of the CompactRF module. The corner pins (1,18,19,36) are labeled directly on the module. NC NC NC NC \Config SYNC RSSI1 RSSI2 RSSI3 Rx Mode Tx Mode PGM GND GND GND GND GND AVcc 10 11 12 13 14 15 16 17 18 T M CompactRF 900MHz 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 AVcc GND ARSSI NC NC \Reset DVcc GND TxD RxD GND DSR CTS DCD RTS DTR SCK \Sleep Figure 1 - Pinout (Top View) Pin Name No. Description I/O ARSSI 34 Provides an analog level of the received signal strength. This is an uncalibrated signal, and will provide only rough measurements of signal strength. AVcc 18,36 Positive Supply for Radio Circuitry. See Section 2.1 for DC Characteristics \Config Momentarily assert low to enter configuration mode. See Section 2.2 CTS 24 RS-232 Clear to Send. Active low (TTL level) output. See Appendix B for a complete description of all RS-232 signals. DCD 23 RS-232 Data Carrier Detect. Active low (TTL level) output. DSR 25 RS-232 Data Set Ready. Active low (TTL level) output. CompactRF TM Operating Manual: Chapter 2 Electrical/Physical CompactRF TM Pin Name No. Description I/O DTR 21 RS-232 Data Terminal Ready. Active low (TTL level) input. DVcc 30 Positive Supply for Logic circuitry and I/O pins. See Section 2.2 for DC Characteristics GND 13-17 26,29, 35 Ground reference for logic, radio and I/O pins. PGM 12 Programming Status indicator. This output is for factory use only, and should normally be left disconnected. \Reset 31 Active low reset input to the module. See Section 2.3 for timing information. SYNC Active high output indicates the modem is synchronized with at least one other modem RSSI1 Receive Signal Strength Indicator 1. This output is the first of the three RSSI indicators to become active high as the signal strength increases. See Table 2 for details RSSI2 Receive Signal Strength Indicator 2. This output is the second RSSI indicator to become active high as the signal strength increases. See Table 2 for details. RSSI3 Receive Signal Strength Indicator 3. This output is the last RSSI indicator to become active high as the signal strength increases. See Table 3 for details. RTS 22 RS-232 Request to Send. Active low (TTL level) input. RxD 27 RS-232 Receive Data. TTL level output. RXMODE 10 Active high output indicates module is receiving data over the RF channel. SCK 20 ISP Programming Clock. Used in conjunction with RxD and TxD when upgrading the FLASH-based firmware. TxD 28 RS-232 Transmit Data. TTL level input. TXMODE 11 Active high output indicates module is transmitting data over the RF channel. \Sleep 19 Assert low to put the unit to sleep. See Section 2.3 for timing information. NC 1-4, 32,33 No Connect Operating Manual: Chapter 2 Electrical/Physical For detailed mechanical drawings, refer to Appendix H 2.2 DC Characteristics Sym Characteristic Min Typ Max Units AVCC Radio Supply Voltage 4.9 5.0 5.5 DVCC Logic Supply Voltage 4.75 5.0 5.5 VPOT Power On Reset Threshold Voltage 1.8 2.2 VRST Reset Pin Threshold Voltage AICCR Radio Supply Current in Receive Mode 54 60 66 mA AICCT Radio Supply Current at 1mW Transmit 68 75 82 mA Radio Supply Current at 10mW Transmit 96 107 118 mA Radio Supply Current at 100mW Transmit 185 206 227 mA Radio Supply Current at 1W Transmit 517 575 633 mA DVCC/ AICCT AICCT AICCT AISL Radio Sleep Current DICC Logic Supply Current DISL Logic Sleep Current VIL Input Low Voltage (Pins 5,19,21,22,28) -0.5 .3DVCC VIH Input High Voltage (Pins 5,19,21,22,28) 0.6VCC VCC+.5 VOL Output Low Voltage (Pins 6-11,23-25,27) 0.6 VOH Output High Voltage(Pins 6-11,23-25,27) ISRCE Sourcing Current (Pins 6-11,23-25,27) Per Pin CompactRF 500 22 25 uA 28 1.0 TM mA mA 4.2 10 mA Operating Manual: Chapter 2 Electrical/Physical 2.3 AC Characteristics Sym Characteristic Min Typ Max Units TTOUT Reset Delay Time-Out Period 12.8 16.0 19.2 ms TCFG \Config. pulse duration TS2SD \Sleep low to internal sleep delay TSN Snooze duration 10 ms TSNIFF Sniff duration 100 us TWDLY \Sleep high to internal wakeup See Note ms See Note TSN ms ms Note: The minimum duration for TCFG is one hop interval. The hop interval is set by the user, and is stored in register S109. The maximum delay for TS2SD is also one hop interval. Figure 2 provides timing information for both power-up reset and the \Reset line operation. A fixed internal reset delay timer of roughly 16ms is triggered as the VPOT or VRST threshold is reached. DVCC VPOT \Reset VRST Internal Reset TTOUT Figure 2. Reset Timing Figure 3 illustrates the sleep operation for the CompactRF. When the \Sleep line is asserted, the modem will internally go to sleep within one hop interval. While sleeping, the modem will “sniff” every 10 ms to check if the \Sleep line has again gone high. If the \Sleep line is low, the modem goes back to sleep. If it is high, the modem wakes up and resumes normal operation. \Sleep TS2SD \Internal Sleep TSNIFF TSN TWDLY Figure 3. Sleep/Wakeup Timing CompactRF TM Operating Manual: Chapter 2 Electrical/Physical 10 CompactRF TM Operating Manual: Chapter 2 Electrical/Physical 3. Modes of Operation The CompactRFTM modem can be easily configured to meet a wide range of needs and applications. The module is designed such that all communication is through one serial port (Pins 21 to 28 on the module). This port has two functions: 1. It provides the asynchronous interface with the host equipment for data that is sent/received on the RF channel. When operating in this fashion, the module is said to be in data mode. 2. It is also used for configuring and programming the module. When operating in this fashion, the module is said to be in command mode. In addition to data mode and command mode, there is a third mode of operation called sleep mode. The module will always be in one of these three modes. 3.1 Data Mode Data mode is the normal operating mode of the CompactRF. When in data mode, the CompactRF is communicating with other CompactRF modules, and facilitating wireless asynchronous serial communication amongst two or more terminal devices. There are three basic elements to any CompactRF communications network: • One module configured as the Master • Zero or more modules configured as Repeaters • One or more modules configured as Slaves The function of the Master is to provide synchronization for the entire network, and to control the flow of data. There is always one Master per network. The Master is the ultimate destination for all data collected at the various Repeater’s and Slave’s serial ports. With the network set up for Point-to-Multipoint communication, all data received at the Master’s serial port is transmitted to every Repeater and Slave in the network. The CompactRF is a frequency hopping transceiver, meaning that it “hops” to a new frequency after a predetermined time interval. This time interval is a fixed time set by the user, and can range from 14ms to 180ms. The CompactRF hops according to a pseudorandom pattern of 50 different channels. CompactRF TM Operating Manual: Chapter 3 Modes of Operation 11 When configured as a Slave, the CompactRF searches for synchronization with a Master. Network topologies consisting of a single Master and virtually any combination of Slaves and Repeaters may be deployed. The functionality of any particular CompactRFTM can be configured as follows: Network 1 n Master Point-to-Point: The modem is configured to communicate with a single Slave, either directly, or through one or more Repeaters. n Master Point-to-Multipoint: The modem is configured to communicate with one or more Slaves and/or Repeaters. n Slave: The modem is configured to communicate with one Master either directly or through one or more Repeaters.. n Repeater: The modem is configured to pass information from either a Master or another Repeater onto subsequent Repeaters and/or Slaves and vice versa. The Repeater also acts as a Slave in the sense that, like a Slave, it passes information to/from its serial port. Examples of different network topologies are shown in Figure 4. Network 1 shows Point-to-Point communication between a Master and Slave. Network 2 makes use of a Repeater to communicate with the Slave. Network 3 illustrates a simple Point-to-Multipoint network with no Repeaters. Networks 4 and 5 gives examples of Point-to-Multipoint networks consisting of both Repeaters and Slaves. There is effectively no restriction to the number of Repeaters and Slaves that can be added to a network. As seen in Network 4, a Master can communicate directly with both Slaves and Repeaters. Network 2 Network 3 Network 4 3.2 Command Mode Network 5 Figure 4 - Sample Network Topologies. Virtually any Combination of Slaves and Repeaters May be Used. 12 The CompactRF firmware has been designed to allow the user to select between two different Command Mode interfaces: Menu Interface; or, AT Command Interface. The menu interface is ideal for applications which involve human configuration of the operating parameters of the modem. The AT Command interface is more suited for direct interface with another microcontroller or for higher level Windows-based software applications. The CompactRF development board is a useful tool for familiarizing yourself with the various operating parameters and user interface. Reference schematics for the development board can be found in Appendix G. To access the CompactRF’s command mode using the development board: 1. Insert the module into the socket with the antenna connector towards the edge of the board. 2. Attach the supplied antenna. 3. Connect a straight through serial cable between the DB9 connector and the serial port on your PC 4. Apply power to the development board 5. Run any terminal application program such as Hyperterminal 6. Set the serial port to 9600 baud, 8N1 7. Momentarily press the configure (CFG) button CompactRF TM Operating Manual: Chapter 3 Modes of Operation 3.2.1 Menu Interface At this point, you should see a menu similar to the following appear: Microhard Systems Inc CompactRF Configuration 1) Operating Mode S101=1 MasterPP 2) Serial Baud Rate S102=4 9600 3) Network Address S104=255 4) Unit Address S105=65535 5) Hopping Pattern S106=0 6) Encryption Key S107=65535 7) Output Power Level S108=0 1 mW 8) Retry Limit S213=255 9) Hop Interval S109=20 x 0.74 ms = 14 ms D) Autoanswer S0=1 E) Interface A) Handshaking &K3 Enabled N) DTR &D0 Ignored O) DSR &S0 ON in Data Mode S6=0 AT style M) DCD &C1 ON when sync'd S2=43 S3=13 S4=10 S5=8 Type AT for AT interface or hit Enter for menu You now have the option of choosing between the menu interface, or the AT Command interface. For menu operation, hit ENTER. You should see the following prompt: Enter Command : Now, the CompactRF will respond to your menu selection. For example, to change the unit’s Operating Mode, press the 1 key. The following sub-menu will appear: Operating Mode * 1) MasterPP Menu selections are immediately stored to the module’s non-volatile memory. 2) SlavePP ESC to exit Select Operating Mode : The instant a selection is made, it is immediately stored into the module’s non-volatile memory. 3.2.2 AT Command Interface The CompactRF may also be controlled through an AT Command line interface, using a command set which is very similar to a traditional Hayes telephone modem command set. For AT Command operation, instead of hitting ENTER at the prompt, type AT. The characters ‘AT’ are known as the attention characters and must be typed at the beginning of each command line. The modem should respond with OK. Illustrating the same example as above to configure the Operating Mode using AT Commands, type the following: ATS101=2 The modem should respond with ’OK.’ The above command will set the operating mode to SlavePP (Slave Point to Point). CompactRF TM Operating Manual: Chapter 3 Modes of Operation 13 When using AT Commands, use the &W command to store the most current settings to memory. With AT Commands, the settings are not immediately stored to non-volatile memory, therefore if the modem is powered down at this point, the Operating Mode would revert to its previous value. To store any recently updated command registers, the following “write” command must be entered. AT&W 3.3 Switching Between Command and Data Modes The method for switching between data and command modes depends on which interface you are using (Menu or AT). There is a parameter called “Interface” (Menu item E) which defines whether the modem is currently operating in AT mode or Menu mode. 3.3.1 Switching Between AT Command Interface and Data Mode Your modem must be in Command Mode for it to execute a command. If you send characters when the modem is in Data Mode, the modem transmits the characters over the air. Depending on its settings, the modem will either power up in Command Mode or Data Mode. Normally, when first received from the factory, the unit will power up in Command Mode. In this mode of operation, the module “autobauds,” meaning that it will adapt to the baud rate of the DTE equipment to which it is connected. Therefore, when in Command Mode, you may change the baud rate of your equipment, and the CompactRF will automatically adjust to this baud rate once an AT string is issued. The new baud rate is stored in register S102. Several baud rates ranging from 2400 to 19200 may be selected. You can place the modem into Data Mode either by: 14 • Issuing the answer command (ATA ); or, • Issuing the online command (ATO ). CompactRF TM Operating Manual: Chapter 3 Modes of Operation The modem will now attempt to communicate with other CompactRF modules. While in Data Mode, the modem will communicate through the serial port at the same baud rate as was last used in Command Mode2. To return to Command Mode, you can either: The escape sequence will not be accepted unless both the CompactRFTM and the terminal are set to the same baud rate • Send the escape sequence. (The escape sequence consists of 1 second of inactivity, followed by the characters ‘+++’ followed by another second of inactivity.); or, • Toggle the DTR line (depending on the &D parameter see pg 11). The escape sequence must be issued at the baud rate that the modem has been set to. If the modem is set to 19200 baud, and the escape sequence is issued at 9600 baud, for example, the modem will not recognize it, and will not go into Command Mode. \SLEEP \CONFIG 3.3.2 Switching Between Menu Interface and Data Mode DATA MODE \CO NF IG \SLEEP \SLEEP \SL EE ESC \SLEEP SLEEP MODE \SLEEP COMMAND MODE To switch back to Data Mode, from the main menu, hit the ESC key. You should see the response “Running...” The modem will run in Data Mode at the baud rate setting defined by Menu Item 2) Serial Baud Rate. 3.4 Sleep Mode ESC \SLEEP \SLEEP Figure 5a - Menu Interface State Diagram \SLEEP or A TO Com man d) Esc DT ape R o Seq r uen ce DATA MODE (ATA \SLEEP SLEEP MODE \SLEEP Figure 5b - AT Interface State Diagram TM As mentioned at the beginning of this chapter, the CompactRF has a sleep mode of operation. Figure 5 is a state diagram representation of the three modes of operation. Figure 5a is the menu interface state diagram, and Figure 5b is the AT interface state diagram. The CompactRF enters into Sleep Mode when \SLEEP is asserted (active low). The module remains in Sleep Mode until this line is deasserted. See Chapter 2 for timing information. When in Sleep Mode, the module drives all outputs pins (Pins 6-11,23-25,27) at their inactive levels. \SLEEP \SLEEP \SLEEP COMMAND MODE CompactRF When configured for Menu Interface operation, the CompactRF may be placed into Command Mode from Data Mode by momentarily asserting the \Config line. This line runs out to a pushbutton on the development board. Press this button and wait for the menu interface to appear on the screen. The terminal must be set to 9600 baud when using the menu interface. It is possible to enter into Data Mode at a different baud rate from what is currently being used in Command Mode by issuing the command ATS102=x, where x is one of the valid baud rates. Care must be taken when setting the baud rate in this manner. If you issue another AT string after attempting to set the baud rate using ATS102 , the modem will again autobaud and automatically revert to the baud rate of the host equipment. For example, if your equipment is running at 9600 baud and you wish to set up the modem to run at 19200 baud, the following command line entry would achieve this: ATS102=2&WA The first part (S102=2) sets the baud rate to 19200. The next characters (&W) write this baud rate to memory. The last character (A) puts the modem into Data Mode. Once in Data Mode, the modem is unable to autobaud, and is fixed at 19200 baud. By combining several commands into one command line entry, and then immediately putting the modem online, the modem is not given a chance to autobaud back to 9600. Operating Manual: Chapter 3 Modes of Operation 15 16 CompactRF TM Operating Manual: Chapter 3 Modes of Operation 4. Configuration This chapter provides a detailed description of the various operating parameters of the CompactRF. Section 4.1 provides a quick-start approach which outlines the minimum requirements for establishing communication between two CompactRF modules. The settings will not necessarily provide optimal performance for your application, but will verify that the modules are functioning correctly. Section 4.2 describes the AT Command interface. Section 4.3 describes the set of registers which are unique to AT operation, and not used in menu mode. Section 4.4 covers all parameters that are common to both the AT Command interface and the Menu interface. 4.1 Quick Start Approach Whether you are using the AT Command interface or the Menu interface, there are several parameters that must be set in order to establish communication between a pair of CompactRF modules. The CompactRFTM is equipped with four standard factory default settings. Instead of manually configuring each individual operating parameter, a global command may be used to quickly configure the modem for a particular type of operation. For example, to quickly implement Network 1, Factory default 1 would be applied to the Master, and Factory default 2 would be applied to the Slave. To quickly set up Network 2, apply Factory 1 to the Master, Factory 3 to the Repeater, and Factory 4 to the Slave. These defaults will get you started and only ensure that a link can be established, but do not necessarily provide the best performance. Optimization of the communications link is discussed in later sections. To implement the basic network illustrated in Figure 6, Network 1, Network 1 Using AT Commands Using Menu Interface Connect a straight-through serial cable between the development board and the terminal Connect an antenna to the module Network 2 Power up the development board Figure 6. Basic Networks See Section 3.3 If you have problems getting into Command Mode. Configure the unit to Factory Setting 1 by typing AT&F1 . This puts the unit into Master Point-to-point mode. Store these settings to memory by typing AT&W . Put the modem into Data Mode by typing ATA (or ATO) Configure the unit to Factory Setting 1 by selecting menu option F). You should see the following: Factory Settings 1) Factory Master 2) Factory Slave 3) Factory Slave Through Repeater 4) Factory Repeater * 5) Manual Select menu item 1) Put the modem into Data Mode by pressing the ESC key. Perform above steps for the second unit, using Factory Setting 2 instead of Factory Setting 1. This will configure the second unit as a Slave. CompactRF TM Operating Manual: Chapter 4 Configuration 17 The units should now be communicating. Remember, the parameters defined by Factory Settings 1 and 2 will likely not be the most ideal for your application, but will quickly allow you to test the units. A complete summary of the settings defined by all four factory settings can be found in Appendix C. Factory Default Settings. Settings are not immediately stored in non-volatile memory when using AT Commands, therefore, the command &W is issued to store the current configuration into non-volatile memory. Settings are retained even after powering down. All user selectable parameters for the CompactRFTM are described in detail in Section 4.4: Configuration Settings. Checking the Link To check if the units are communicating, observe the LED indicators on the development board. If the link is good, up to three RSSI LED’s on the Master and Slave modems should be active; and if the link is absent (due to a fault at one end or another, such as misconfiguration), the LED’s will be in either “scanning mode” or inactive. Characters typed at the Master terminal should appear at the Slave’s terminal, and vice versa. Also, verify that the RX LED blinks as packets of data are received at the Master modem. As data is sent from Slave to Master, the RX indicator should blink on as correct packets of data are received. It is recommended that if the CompactRFTM will be deployed in the field where large distances separate the units, the modems should be configured and tested in close proximity (e.g., in the same room) first to ensure a good link can be established and settings are correct. This will facilitate troubleshooting, should problems arise. 4.2 AT Commands Several AT Commands are supported by the CompactRFTM. The commands discussed in this section do not have a menu interface equivalent. More commands and S-Register settings are discussed in Sections 4.3 and 4.4. To make the command line more readable, you can insert as many spaces as desired. The command line holds up to 16 characters, not including the AT prefix. If you want to send more than one command line, wait for a response before entering the AT prefix at the start of the next command line. To re-execute the previous command, enter A/. The modem will execute the previous command line. When in Command Mode, the modem “autobauds”, meaning that it will automatically adjust to the baud rate of the terminal. You may change the terminal baud rate while in Command Mode without losing communication with the modem. For the AT command protocol, an escape sequence consists of three consecutive escape codes preceded and followed by at least 1 second of inactivity. Typically, the ‘+’ character is used as the escape code. +++ 18 preceded and followed by 1 second of inactivity CompactRF TM Operating Manual: Chapter4 Configuration Note that the terminal must be configured to the same baud rate as the modem in order for the modem to recognize the escape sequence. The modem is unable to “autobaud” while in Data Mode. The following is a description of all available commands. ‘*’ denotes standard factory settings. All of the following commands must be preceded by “AT”. Answer The A command causes the modem to attempt to connect with another remote modem (Type ATA ). Command Echo Your modem is preset to return (or echo) commands to the host microprocessor when in Command Mode. E0 *E1 No Command Echo Command Echo Identification The I command returns various modem information settings. I0 I2 I3 I4 I5 I6 Product Code (CompactRF) Issue ROM Check (OK or ERROR) Product Identification (Firmware Version) Firmware Date Firmware Copyright Firmware Time On-line Mode The O command attempts to put the modem online and communicate with a remote modem. Quiet Mode Your modem is preset to send responses when it executes commands, and there after to keep the host informed of its status. *Q0 Q1 Enable modem responses Disable modem responses Result Codes display Your modem can either display result codes as words or numbers. V0 *V1 Display Result Codes as numbers Display Result Codes as words Connection Result This parameter determines the modem response at the transition from Data Mode to Command Mode *W0 W1 W2 Reports computer (DTE) baud rate as CONNECT xxxx Reports wireless rate between modems as CARRIER xxxx. Reports modem (DCE) baud rate as CONNECT xxxx Reset and load stored configuration The Z command resets the modem and loads the stored configuration. CompactRF TM Operating Manual: Chapter 4 Configuration 19 &V View Configuration The &V command displays all S registers and their current values. &E Framing Error Check NOT YET IMPLEMENTED This command enables or disables Framing Error Check. When enabled, the modem looks for the stop bit. If the stop bit is absent, the byte is thrown out. When enabled, the modem also does a parity check. Note that the data format (number of data bits, parity type, and number of stop bits) is defined by S register 110. *&E0 &E1 &W Disable Framing Error Check Enable Framing Error Check Write Configuration to Memory The &W command stores the active configuration into the modem’s nonvolatile memory. Sxxx? Read S register value This command causes the modem to display the current setting of S register xxx. Sxxx=yyy Set S register value (see section 3.3 S-Registers) This command sets the specified S register to a value specified by yyy. AT Command Result Codes The CompactRFTM module can either display the results of a command as either text strings or numerical data. The following chart shows resulting text string and corresponding numeric result. 10 12 13 14 15 17 18 33 62 64 20 OK NO CARRIER ERROR CONNECT 2400 CONNECT 3600 CONNECT 4800 CONNECT 7200 CONNECT 9600 CONNECT 14400 CONNECT 19200 CONNECT 28800 CONNECT 38400 CONNECT 57600 CONNECT 115200 CARRIER 45000 CARRIER 20000 CompactRF TM Operating Manual: Chapter4 Configuration 4.3 AT Registers The parameters described in this section apply to AT Command operation only. S Register 0 - Auto Answer If this register is set to zero, the modem will power up in command mode. If this register is non-zero, the modem will power up in data mode. S Registers 2 through 5 cannot be stored to nonvolatile memory. S Register 2 - Escape Code This register contains the ASCII value of the escape character. The default value (decimal 43) is equivalent to the ASCII character ‘+’. Values greater than 127 disable the escape feature and prevent you from returning to the Command Mode. This register cannot be stored to nonvolatile memory. If the modem is reset, or powered down, the default value is restored. Default is ‘+’ (decimal 43). S Register 3 - CR Control Code This register contains the ASCII value of the carriage return character. This is the character that is used to end the command line and is also the character that appears after the modem sends a response. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default value is restored. Default is ‘CR’ (decimal 13). S Register 4 - Linefeed Control Code Register S4 sets the ASCII value of the linefeed character. The modem sends the linefeed character after sending a carriage return character when sending text responses. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default value is restored. Default is ‘LF’ (decimal 10). S Register 5 - Backspace Control Code Register S5 sets the ASCII value of the backspace character. This character is both the character created by entering BACKSPACE and the character echoed to move the cursor to the left. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default value is restored. Default is ‘BS’ (decimal 8). CompactRF TM Operating Manual: Chapter 4 Configuration 21 4.4 Configuration Settings The parameters described in this section affect the operating characteristics of the CompactRF module. All the settings described in this section can be configured using either the AT Command interface or the menu interface. DCD (Data Carrier Detect) AT Menu &C The &C command controls the modem’s DCD output signal to the host microprocessor. This command determines when the DCD is active. &C0 *&C1 &C2 DCD is always ON DCD on when modems are synchronized. DCD is always on when unit is configured as Master. DCD used for output data framing and Modbus mode. See page 24 for details. DTR (Data Terminal Ready) AT Menu &D The &D command controls what action the modem performs when the DTR input line is toggled. The DTR input is controlled by the host microprocessor. *&D0 &D1 &D2 &D3 DTR line is ignored Not Supported DTR disconnects and switches to Command Mode DTR disconnects and resets modem. Modem will remain in this state until DTR again goes active. Load Factory Default Configuration AT Menu &F The &F command resets the modem and loads the default factory configuration. &F1 &F1 Master &F2 &F2 Slave &F3 &F4 &F1 Master 22 &F3 Repeater &F4 Slave Master Point-to-Multipoint. Designed to communicate with modems configured as &F2 or &F3. Slave. Designed to communicate with another modem configured as &F1. Repeater. Designed to communicate with modems configured as &F1 and &F4. Slave working with factory default Repeater and factory default Master. Communicates directly with Repeater configured as &F3. CompactRF TM Operating Manual: Chapter4 Configuration Handshaking AT Menu &K This command controls the handshaking between the modem and host microprocessor. &K0 &K2 *&K3 Disable handshaking RTS/CTS input data framing. See page 33 for details. Enable hardware handshaking (RTS/CTS) DSR (Data Set Ready) AT Menu &S This command controls the DSR line for the modem, and determines when it is active &S0 *&S1 DSR is always ON DSR is ON in Data Mode, OFF in Command Mode Operating Mode Only one Master can exist for each network. AT Menu S101 The Operating Mode (register S101) partly defines the “personality” of the CompactRFTM module. Allowable settings for this register are 1 through 4 as follows:. • • • • S101=1 S101=2 S101=3 S101=4 Master Point to Multipoint Master Point to Point Slave Repeater The default for this register depends on which factory default is selected as shown below: • • • • Default for Factory Setting &F1 is 1 (Master Point-to-Multipoint) Default for Factory Setting &F2 is 3 (Slave) Default for Factory Setting &F3 is 4 (Repeater) Default for Factory Setting &F4 is 3 (Slave) 1)Master - Point to Multipoint. In any given network, there is always only one Master. All other units should be configured as either Slaves or Repeaters. When defined as a Point-to-Multipoint Master, the modem broadcasts data to all Slaves and Repeaters in the network, and is also the ultimate destination for data transmitted by all Slaves and Repeaters. In addition, the Master defines the following network parameters to be utilized by all other modems in the network (See the appropriate sections for a complete description of these parameters): n Maximum Packet Size (S112) n Minimum Packet Size (S111) n Link Handshaking (S122) n Wireless Link Rate (S103) n Hop Interval (S109) CompactRF TM Operating Manual: Chapter 4 Configuration 23 2)Master - Point to Point. This mode of operation is identical to Master Point-to-Multipoint, with the exception that the Master only broadcasts to one particular Slave or Repeater. The modem with which communication occurs is defined by the Unit Address (S105). For example, if a Slave has been assigned Unit Address 100, and the Master wishes to communicate with that Slave, the Master must also be assigned a Unit Address of 100. If there are Repeaters in the network, they will pass the packet through to the Slave, and vice versa. Because Repeaters also have Slave functionality (i.e., a Repeater can be connected to a terminal), the Master can choose to communicate solely with a Repeater. This would be accomplished by assigning the same Unit Address to both the Master and the Repeater. Network 50 Hop Pattern 2 PHP=1 Master PHP=1 SHP=2 PHP=2 Slave Repeater Hop Pattern 1 Figure 7 - Repeater Operation Hop Pattern 3 Repeater Slave PHP=2 PHP=3 SHP=3 Master PHP=1 HopPattern 1 Repeater PHP=1 SHP=2 Slave PHP=2 Hop Pattern 2 Figure 8 - A Network Utilizing Three Hopping Patterns If there is no DTE connected to the Repeater, turn off handshaking (&K0) and set the baud rate to 115K. 24 3)Slave. Up to 65534 Slaves may exist in a network, all of which communicate with the common Master (either directly or via Repeater(s)). Slaves cannot directly communicate with other Slaves, nor can they acknowledge packets of data sent by the Master. Clearly this would cause conflicts when there are multiple Slaves. The Master does, however, send acknowledgements to all messages it receives from Slaves. The Master initiates communications by sending a broadcast message to all Slaves. All Slaves are free to respond in a “Slotted ALOHA” fashion, meaning that each Slave can choose one of several windows in which to transmit. If there happens to be two Slaves attempting to talk at the same time, the Master may not receive the data, and the Slaves therefore would not get an acknowledgement. At this point, the Slaves would attempt to get the information through at random time intervals, thus attempting to avoid any more conflicts. Special parameters which control the Slave’s response characteristics can be modified with S Registers S115 and S213. 4) Repeater. A more precise title would be Repeater/Slave, because a Repeater also has much of the same functionality as a Slave. A terminal can be connected at the Repeater location and communicate with the Master terminal. There is no restriction to the number of Repeaters in a network, allowing for communication over virtually limitless distances. The presence of one Repeater in a network automatically degrades system throughput by half. Additional Repeaters, regardless of the quantity, do not diminish system throughput any further. To understand Repeater operation, consider the module as belonging to two hopping patterns at the same time: The Primary Hopping Pattern and the Secondary Hopping Pattern. In Figure 7, the Master belongs to Hopping Pattern 1, and communicates with the Repeater on this hopping pattern. The Slave belongs to Hopping Pattern 2, and communicates with the Repeater on this hopping pattern. The whole system belongs to Network 50 (i.e., all units must be assigned the same Network Address (S104), which in this case was selected to be 50. Note that Slaves and Master only communicate on their respective Primary Hopping Pattern. Repeaters communicate on the Primary Hopping Pattern when communicating with the Master (or with another Repeater between itself and the Master). Repeaters communicate on their Secondary Hopping Pattern when communicating with Slaves (or with another Repeater between itself and the Slaves). Figure 8 shows another example. If the Repeater is not also being used as a Slave (there is no DTE connected to the serial port), it is recommended that the Repeater’s baud rate be set to 115K, and that handshaking be disabled (&K0). This will help ensure a smooth flow of data through the network. CompactRF TM Operating Manual: Chapter4 Configuration Serial Baud Rate AT Menu S101 The Serial Baud Rate is the current speed that the modem is using to communicate with the DTE. When the AT command prefix is issued, the modem performs an ‘autobaud’ operation and determines what the current DTE baud rate is set to. The S register value returns the current setting of the DTE baud rate. The possible values are: *1 10 11 115200 57600 38400 28800 19200 14400 9600 7200 4800 3600 2400 It is generally advisable to choose the highest rate that your terminal equipment will handle to maximize performance, unless a limitation on the available bandwidth is desired. If the DTE is a personal computer, the port can usually be used reliably at 115200. The Master determines the Wireless Link Rate. This setting on all other modems is ignored.. CompactRF TM Operating Manual: Chapter 4 Configuration 25 Select a Network Address and assign it to all units which will be included in the network. Network Address AT Menu S104 The Network Address defines the communications network to which individual units can be a part of. By establishing a network under a common Network Address, the network can be isolated from any other concurrently operating network. As well, the Network Address provides a measure of privacy and security. Only those units which are members of the network will participate in the communications interchange. Valid values for the Network Address range from 0 to 65535, inclusive. To enhance privacy and reliability of communications where multiple networks may operate concurrently in close proximity, it is suggested that an atypical value be chosen – perhaps something meaningful yet not easily selected by chance or coincidence. Default is 1. Unit Address Use the same Unit Address on both units for point-topoint mode. In multipoint mode, set each Slave and Repeater to a different Unit Address. Valid Unit Addresses are 1 to 65535. AT Menu S105 In point-to-point operation, the Unit Address on both the Master and Slave (or Repeater) units must be the same. In a multipoint system, the Unit Address uniquely identifies each Slave and Repeater from one another. Each unit in a multipoint system must have a unique Unit Address ranging from 1 to 65535. Do not use 0 as a Unit Address, and do not use a Unit Address more than once within the same Network. This is required because the Master must be able to acknowledge each unit individually, based on the Unit Address. AT Menu Primary Hopping Pattern S106 Secondary Hopping Pattern S206 Since the CompactRFTM is a frequency-hopping modem, the carrier frequency changes periodically according to one of 30 pseudo-random patterns, defined by the Primary and Secondary Hopping Patterns. Valid entries for each are 0 through 29. The concept of Primary and Secondary Hopping Patterns was introduced in the discussion of S Register 101 (Operating Mode). Using the designations M[a,] Rx[a,b] and Sx[a] where: - M indicates Master; - R indicates Repeater; - S indicates Slave; - x is the Unit Address; - a is the primary hopping pattern; and, - b is the secondary hopping pattern; 26 CompactRF TM Operating Manual: Chapter4 Configuration the following diagrams illustrate the methodology for deploying simple to complicated networks: Master Slave Master Repeater Master Repeater1 M[1] ←→ S1[1] M[1] ←→ R1[1,2] ←→ S2[2] M[1] ←→ R1[1,2] ←→ R2[2,3] ←→ S3[3] M[1] ←→ R1[1,2] ←→ R2[2,3] ←→ R3[3,4] ←→ S4[4] Slave Repeater2 Slave It is reasonable to consider a Repeater as being both a Slave and a Master, alternating between Primary and Secondary Hopping Patterns as the unit changes channel. Consider R1 in the illustration below. When communicating with the Master, R1 is acting like a Slave on Primary Hopping Pattern 1. When communicating with R2 and S4, R1 is acting like a Master on Secondary Hopping Pattern 2. If multiple Repeaters are used, they should have different Secondary Hopping Patterns: ←→ R1[1,2] M[1] Slaves and Masters do not use Secondary Hopping Patterns ←→ R2[2,5] ←→ S4[2] ←→ R5[1,3] ←→ R6[3,6] ←→ R8[1,4] ←→ S9[4] ←→ S3[5] ←→ S7[6] Note that all units have a unique Unit Address. Remember to assign a unique Unit Address (1 to 65535) to each unit in the system Networks of any complexity can be created by linking multiple Repeaters and Slaves: ←→ R1[1,2] ←→ M[1] ←→ S2[2] ←→ S3[2] ←→ R5[3,6] R4[1,3] ←→ ←→ S11[1] ←→ S12[1] R8[3,7] ←→ S6[6] ←→ S7[6] ←→ R9[7,8] ←→ S10[8] With a limitation of 62 hopping patterns, one might suspect that there is a limitation to the number of repeaters in a system. However, if the units are far enough away from one another, hopping patterns may be reused in different sections of the network, without causing interference. CompactRF TM Operating Manual: Chapter 4 Configuration 27 All units within a network must use the same encryption key. Encryption Key AT Menu S107 The Encryption Key provides a measure of security and privacy of communications by rendering the transmitted data useless without the correct key on the receiver. Valid Encryption Keys range from 0 to 65535. Keep in mind that all units within the network must use the same key for communications to succeed. Output Power Level AT Menu S108 The Output Power Level determines at what power the CompactRFTM transmits. The CompactRFTM can operate with very low power levels, so it is recommended that the lowest power necessary is used; using excessive power contributes to unnecessary “RF pollution”. The allowable settings are: *2 1 mW 10 mW 100 mW 1000 mW Ideally, you should test the communications performance between units starting from a low power level and working upward until the RSSI is sufficiently high and a reliable link is established. Although the conditions will vary widely between applications, typical uses for each setting are described below: Power Use 1 mW For in-building use, typically provides a link up to 300 feet on the same floor or up/down a level. Outdoors, distances of 1 km can be achieved if high-gain (directional) antennas are placed high above ground level and are in direct line-of-sight. 10 mW 200-500 ft indoors, 2-5 km outdoors. 100 mW 400-800 ft indoors, 4-8 km outdoors. 1000 mW Typically provides communications up to a distance of 1000 feet or (1 W) more in-building on the same floor or up/down a few levels, depending on building construction (wood, concrete, steel, etc.). In ideal line-of-sight conditions, up to 16 km or more can be achieved. Note that only an antenna with a gain of no more 6 dBi may be used. Any higher is a violation of FCC rules. See IMPORTANT warning below. 28 CompactRF TM Operating Manual: Chapter4 Configuration IMPORTANT: FCC Regulations FCC Regulations allow up to 36 dBi effective radiated power (ERP). Therefore, the sum of the transmitted power (in dBm), the cabling loss and the antenna gain cannot exceed 36 dBi. 1 mW = 0 dBm 10 mW = 10 dBm 100 mW = 20 dBm 1000 mW = 30 dBm For example, when transmitting 1 Watt (30 dBm), with cabling losses of 2 dB, the antenna gain cannot exceed 36 - 30 + 2 = 8 dBi. If an antenna with a gain higher than 8 dBi were to be used, the power setting must be adjusted appropriately. Hopping Interval The hopping interval is controlled by the master. The slave and repeater units will use the hopping interval setting from the master. AT Menu S109 This option determines the frequency at which the modems change channel. Note that the Master controls this parameter for the entire network. This setting is ignored in units configured as Slaves or Repeaters. The allowable settings are 20 to 255. There is a multiplying factor of 0.74ms. For example, if you set the Hopping Interval to 20, the actual hopping interval will be 20 x 0.74ms = 14.8ms. See Appendix D for optimal Hopping Interval settings in relation to packet size and link rate. Data Format AT Menu S110 This register determines the format of the data on the serial port. Allowable settings are: *1 10 11 CompactRF TM Operating Manual: Chapter 4 Configuration 8 bits, No Parity, 1 Stop 8 bits, No Parity, 2 Stop 8 bits, Even Parity, 1 Stop 8 bits, Odd Parity, 1 Stop 7 bits, No Parity, 1 Stop 7 bits, No Parity, 2 Stop 7 bits, Even Parity, 1 Stop 7 bits, Odd Parity, 1 Stop 7 bits, Even Parity, 2 Stop 7 bits, Odd Parity, 2 Stop 9 bits, No Parity, 1 Stop 29 AT Menu Packet Minimum Size S111 Packet Maximum Size S112 Packet Character Timeout S116 These settings determine the conditions under which the modem will transmit accumulated data over the air. S Register 111 - Minimum Size The Minimum and Maximum Packet Size is controlled by the Master. The Slave and Repeater units will use the Minimum and Maximum Packet Size setting from the Master. Valid entries for this register are 1 to 255 bytes, which defines the minimum number of bytes to receive from the DTE before encapsulating them in a packet and transmitting over the air. Note that the minimum packet size for all modems in the network is determined by the Master only. This setting is ignored in all Slave and Repeater modems. The default is 1 byte. S Register 112 - Maximum Size This setting has a range of 2 to 255, and defines the maximum number of bytes from the DTE which should be encapsulated in a packet. This value should be greater than the minimum packet size, but not smaller than is necessary for reliable communications. If the wireless link is consistently good and solid, a maximum size of 255 will yield the best throughput (depending on the higher level protocols of the connected equipment). However, if the link is poor (e.g., experiencing excessive interference) and data is frequently retransmitted, the maximum packet size should be reduced. This decreases the probability of errors within packets, and reduces the amount of traffic in the event that retransmissions are required. Note that the maximum packet size for all modems in the network is determined by the Master only. This setting is ignored in all Slave and Repeater modems. The default is 255 bytes. S Register 116 - Packet Character Timeout This register has valid entries of 0 to 254 milliseconds. The Packet Character Timeout timer looks for gaps in the data being received from the DTE. The timer is only activated after the Minimum Packet Size has been accumulated in the modem. After which, if the timer detects a gap in the data exceeding the Packet Character Timeout value, the modem will transmit the data. The CompactRFTM will accumulate data in its buffers from the DTE until one of the following requirements is met (whichever occurs first): • The Maximum Packet Size (in bytes) has been accumulated; • The Minimum Packet Size has been accumulated AND the Packet Character Timeout interval has elapsed. The default for the Packet Character Timeout is 9 ms. If set to 0 ms, the unit will buffer exactly the minimum packet size before transmitting. 30 CompactRF TM Operating Manual: Chapter4 Configuration Packet Retransmissions AT Menu S113 This register applies to both Master and Repeater operation. It does not apply to Slave operation. The Master will retransmit each data packet exactly the number of times defined by the Packet Retransmissions parameter. The Master retransmits once at the beginning of each hopping interval until the limit is reached. This parameter is not necessary in Slave units since all Slaves receive acknowledgement from the Master. As discussed previously, the Repeater effectively behaves as both a Master and a Slave. When the Repeater is tuned to its Secondary Hopping Pattern (acting as a Master), the Packet Retransmissions Parameter comes into play. The Repeater will re-send packets of data on to Slaves or other Repeaters exactly the number of times defined by the Packet Retransmissions parameter. Recipients of the packet will discard any duplicates The valid settings for this parameter are 0 to 255 retransmissions. The default is 2. Packet Retry Limit AT Menu S213 Packet Retry Limit is analogous to Packet Retransmissions, but specifically applies to Slaves and Repeaters. This parameter is not used by the Master. Because the Slave has the advantage of receiving acknowledgements from the Master, it is not necessary to blindly retransmit each packet. If the Slave does not get an acknowledgement on the next hop, it will retransmit its packet. This will continue until the Packet Retry Limit is reached or an acknowledgement is received. If the limit is reached, the modem will give up and discard the data. Valid settings are 0 to 255 retries. The default value is 2. The Repeater makes use of this parameter when it is tuned to its Primary Hopping Pattern and is acting like a Slave. CompactRF TM Operating Manual: Chapter 4 Configuration 31 Packet Repeat Interval AT Menu S115 A parameter that is specific to Slaves and Repeaters is the Packet Repeat Interval. The allowable settings are 1 through 255. The default is 1. This parameter defines a range of random numbers that the Slave will use as the next slot in which it will attempt to send the packet. For example, if this register is set to 7, the Slave will choose a number between one and seven as the next slot in which to transmit. Suppose the random number generator picks 5, then the Slave will transmit in the fifth time slot. A Slave will transmit a maximum of once per hopping interval, however, depending on the duration of the hopping interval and the maximum packet size, more than one slot per hop is potentially available. The Slave will transmit more frequently when a Repeat Interval with a smaller range is selected. Choose 1 to have the Slave transmit in the first available slot. Choose higher intervals for less frequent transmission, or to avoid collisions between many Slaves in the system. Link Handshaking AT Menu S122 Link Handshaking is controlled only by the Master unit. If the Master runs out of free buffers, it will command all Slaves and Repeaters to hold their data. Once the Master is ready to receive data it will allow the Slaves and Repeaters to transmit. Possible values are ‘1’ - Enabled and ‘0’ - Disabled. The default is 1. This register is ignored by all Slave and Repeater units. Modbus Mode AT Menu S117 TM Modbus Mode allows for the CompactRF to be fully Modbus compatible. Please contact Microhard Systems for assistance when configuring the unit for Modbus operation. Optimal Modbus settings rely on several other S Register parameters. The allowable settings for this register are: *0 32 Disabled Enabled CompactRF TM Operating Manual: Chapter4 Configuration AT Menu RTS/DCD Framing 120 DCD Timeout 121 The CompactRFTM supports two special types of data framing: • • Input (or RTS/CTS) Data Framing; and, Output (or DCD) Data Framing Input Data Framing is enabled by configuring the Handshaking Parameter as &K2. This type of framing makes use of the S120 parameter as illustrated in Figure 9. Parameter S120 can be set to any value between 0 and 254 ms. RTS CTS TXD Data going into MHX-910 0 to 1 ms S120 (ms) Figure 9 - Input Data Framing To enable output (DCD) data framing, set the Data Carrier Detect parameter as &C2. This type of framing uses both S120 and S121 registers as shown in Figure 10. Valid ranges for each parameter are 0 to 254 ms. DCD RXD Data leaving MHX-910 S120 (ms) S121 (ms) Figure 10 - Output Data Framing RSSI Reading AT Menu S123 This register displays the average signal strength in dBm over the previous four hop intervals. Valid RSSI readings apply only to units configured as Slave or Repeater. CompactRF TM Operating Manual: Chapter 4 Configuration 33 34 CompactRF TM Operating Manual: Chapter4 Configuration 5. Installation The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. The CompactRF complies with FCC part 15 at the modular level for operation in the license-free 902-928 MHz ISM band. This chapter provides guidelines for installing and deploying equipment which incorporates the CompactRF module. 5.1 Estimating the Gain Margin Successful communication between CompactRF modules is dependent on three main factors: • System Gain • Path Loss • Interference System gain is a calculation in dB describing the performance to be expected between a transmitter-receiver pair. The number can be calculated based on knowledge of the equipment being deployed. The following four factors make up a system gain calculation: 1. Transmitter power (user selectable 0, 10, 20 or 30 dBm) 2. Transmitter gain (transmitting antenna gain minus cabling loss between the transmitting antenna and the CompactRF module) 3. Receiver gain (Receiving antenna gain minus cabling loss between the receiving antenna and the module) 4. Receiver sensitivity (Specified as -103 dBm on the CompactRF module) In the following illustration, the transmitting antenna has a gain of 6 dB, and the receiving antenna has a gain of 3 dB. The cable loss between the module and the antenna is 2 dB on both the transmitting and receiving side. Cable Loss = 2 dB Antenna Gain = 6 dB Cable Loss = 2 dB Antenna Gain = 3 dB Transmitter Receiver 30 dBm Output Power Sensitivity = -103 dBm The power level has been set to 30 dBm (1W) on the transmitter, and the receiver sensitivity for the CompactRF is -103 dBm. System gain would be calculated to be: 30 - 2 + 6 + 3 - 2 + 103 = 138 dB. CompactRF TM Operating Manual: Chapter 5 Installation 35 Base Height (m) Mobile Height (m) Distance (km) When deploying your system, care must be taken to ensure the path loss (reduction of signal strength from transmitter to receiver in dB) between equipment does not exceed the system gain (138 dB in the above example). It is recommended to design for a gain margin of at least 10 dB to ensure reliable communication. Gain margin is the difference between system gain and path loss. Referring to the same example, if the path loss is 100 dB, the gain margin would be 38 dB, which is more than adequate for reliable communication. Path loss is a very complicated calculation which mainly depends on the terrain profile, and the height of the antennas off the ground. The following table provides path loss numbers for varying antenna heights and antenna separation: These numbers are real averages taken from rural environments. They do not apply to urban, non-line-of-sight environments. Distance (km) Base Height (m) Mobile Height (m) Path Loss (dB) 15 2.5 116.5 30 2.5 110.9 15 2.5 124.1 15 117.7 15 10 105 16 15 2.5 135.3 16 15 128.9 16 15 10 116.2 16 30 10 109.6 16 30 122.4 16 30 2.5 128.8 Once the equipment is deployed, you can verify the signal strength by entering into Command Mode and reading Register S123. This register provides the average signal strength in dBm. The minimum strength for communication is roughly -103 dBm. For consistent reliable communication, you should try to deploy the equipment such that signal strength exceeds -95 dBm. 36 CompactRF TM Operating Manual: Chapter 5 Installation 5.2 Antennas and Cabling This section describes the recommended procedure for installing cabling and antennas for use with the CompactRF module. 5.2.1 Internal Cabling The most common method for installing the module is to run a cable from the module’s SMA connector to an N-male bulkhead connector on the chassis of the equipment as shown in Figure 11 N-male connector LMR195 Cable with SMA male connector and N-male bulkhead connector SMA male connector Figure 11. Suggested Internal Cabling With losses of 10.7 dB/100ft, LMR195 is a high quality cable ideal for use with the CompactRF’s SMA connector. Losses are negligible for the short piece used within the chassis. Additional losses up to 0.5 dB may be present in the SMA and N connections. CompactRF TM Operating Manual: Chapter 5 Installation 37 5.2.2 Installing External Cables, Antennas and Lightning Arrestors The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. The installation, removal or maintenance of all antenna components must be carried out by qualified and experienced professionals. Never work on an antenna system when there is lightning in the area. Direct human contact with the antenna is potentially unhealthy when the CompactRF is generating RF energy. Always ensure that the CompactRF equipment is powered down during installation.s Never work on an antenna system when there is lightning in the area. Direct human contact with the antenna is potentially unhealthy when the CompactRF is generating RF energy. Always ensure that the CompactRF equipment is powered down during installation. Surge Arrestors The most effective protection against lightning is to install two lightning (surge) arrestors. One at the antenna, and the other at the interface with the equipment. The surge arrestor grounding system should be fully interconnected with the transmission tower and power grounding systems to form a single, fully integrated ground circuit. Typically, both ports on surge arrestors are N-female. Cabling The following coax cables are recommended: Cable Loss (dB/100ft) LMR 195 10.7 LMR 400 3.9 LMR 600 2.5 Factors to take into consideration when choosing a cable are: • price; • bend radius limitations (the lower performance cables generally can bend more sharply) • performance requirements; and, • distance between the equipment and the antenna. When installing the cable, always begin fastening at the top near the antenna connector/surge arrestor. The cable must be supported at the top with a hose clamp or wrap lock, and at 5 ft intervals down the length of the tower. Over-tightening the fasteners will dent the cable and reduce performance. If properly grounded surge arrestors are not installed at both the top and the bottom of the cable, then the cable should be grounded to the tower at these locations using a cable grounding kit. If the tower is non-conductive, then a separate conductor, physically separate from the cable, should be run down the tower. 38 CompactRF TM Operating Manual: Chapter 5 Installation Antenna Before choosing an antenna, you should have some knowledge of the path loss and the topology of the equipment. If the equipment is in a fixed location and is to communicate with only one other unit also in a fixed location, then a Yagi antenna is suitable. Choose a Yagi with enough gain to ensure adequate gain margin. When deploying the Yagi, point the antenna towards the intended target, ensuring the antenna elements are perpendicular to the ground. If the equipment must communicate with multiple or mobile transceivers, then select an Omni-directional antenna with appropriate gain. The Effective Radiated Power (ERP) emitted from the antenna cannot exceed +36 dBm ERP. To comply with FCC regulations, .you must limit ERP to 36 dBm or less. With the CompactRF set to full power, ERP is calculated as follows: ERP = 30 - (Cabling and Connector Losses) + (Antenna Gain) < 36 Use the guidelines in the previous section for calculating cable and connector losses. If cabling and connector losses are 2 dB, then the maximum allowable gain of the antenna will be 8 dB. External Filter Although the CompactRF is capable of filtering out RF noise in most environments, there are occasions that require external filtering. Paging towers, and cellular base stations in close proximity to the CompactRF antenna can desensitize the receiver. Microhard Systems’ external cavity filter eliminates this problem. The filter has two N-female ports and should be connected in line at the interface to the RF equipment. Weatherproofing Type N connectors are not weatherproof. All connectors should be taped with rubber splicing tape (weatherproofing tape), and then coated with a sealant. CompactRF TM Operating Manual: Chapter 5 Installation 39 40 CompactRF TM Operating Manual: Chapter 5 Installation A. Modem Command Summary The following provides a command summary for the CompactRFTM. Factory settings are denoted with a ‘*’. AT Commands Answer Command Echo E0 No Echo * E1 Command Echo Identification I0 Product Code I2 ROM Checksum test I3 Firmware Version I4 Firmware Date I5 Copyright I6 Firmware Time On-line Mode Quiet Mode * Q0 Enables Result Codes Q1 Disables Result Codes Result Codes Display V0 Display as Numbers * V1 Display as Words Connection Result * W0 Reports DTE as CONNECT xxxx W1 Reports computer (DTE) rate and wireless rate between modems as CARRIER xxxx. W2 Reports DCE as CONNECT xxxx Reset and load stored configuration &C DCD (Data Carrier Detect) &C0 DCD is always on * &C1 DCD is on when modems are synchronized &C2 DCD used for output data framing &D DTR (Data Terminal Ready) &D0 DTR ignored * &D2 DTR disconnects and switches to command &D3 DTR disconnects and resets modem &F Load Factory Default &F1 Master &F2 Slave &F3 Repeater &F4 Slave through Repeater &K Handshaking &K0 Disable Handshaking &K2 RTS/CTS Input Framing * &K3 Enable Handshaking &S DSR (Data Set Ready) &S0 DSR is always on * &S1 DSR on in data, off in command mode &V View Configuration &W Write configuration to memory Sxx? Read S register value Sxx=yy Set S register value Result Codes OK 12 CONNECT 9600 NO CARRIER 13 CONNECT 14400 ERROR 14 CONNECT 19200 CONNECT 2400 15 CONNECT 28800 CONNECT 3600 17 CONNECT 38400 CONNECT 4800 18 CONNECT 57600 10 CONNECT 7200 33 CONNECT 115200 64 CARRIER 20000 62 CARRIER 45000 CompactRF TM S Registers S0 Auto Answer [0...255] 0 = power up in Command Mode, non-zero = power up in Data Mode S2 Escape code [0...255] default ‘+’ S3 CR character [0...255] default S4 Line Feed [0...255] default S5 Backspace [0...255] default S101 Operating Mode 1 - Master Point to Multipoint 2 - Master Point to Point 3 - Slave 4 - Repeater S102 Serial Baud Rate *1 = 115200, 2 = 57600, 3 = 38400 4 = 28800, 5 = 19200, 6 = 14400 7 = 9600, 8 = 7200, 9 = 4800, 10 = 3600, 11 = 2400 S103 Wireless Link Rate 2 = Fast w/o FEC *4 = Fast with FEC S104 Network Address [0...65535] S105 Unit Address [1...65535] S106 Primary Hopping Pattern [0...61] S206 Secondary Hopping Pattern [0...61] S107 Encryption Key [0...65535] S108 Output Power Level 0 = 1 mW, 1 = 10 mW, *2 = 100 mW 3 = 1000 mW S109 Hopping Interval 1 = 8 msec, 2 = 12 msec, 3 = 16 msec, 4 = 20 msec, 5 = 30 msec, 6 = 45 msec, 7 = 80 msec, *8 = 120 msec S110 Data Format * 1 = 8N1, 2 = 8N2, 3 = 8E1, 4 = 8O1 5 = 7N1, 6 = 7N2, 7 = 7E1, 8 = 7O1 9 = 7E2, 10 = 7O2, 11 = 9N1 S111 Packet Minimum Size [1...Maximum Size] S112 Packet Maximum Size [2...255] S113 Packet Retransmissions [0...255] S213 Packet Retry Limit [0...255] S115 Packet Repeat Interval [1..255] Default = 1 S116 Packet Character Timeout [0...254 ms] S117 Modbus Mode *0 = Disabled, 1 = Enabled S120 RTS/DCD Framing Interval [0...254 ms] S121 DCD Timeout [0...254 ms] S122 Link Handshaking [0=Disabled, *1=Enabled] Operating Manual: Appendix A Modem Command Summary 41 42 CompactRF TM Operating Manual: Appendix A Modem Command Summary B. Serial Interface The CompactRFTM uses 8 pins on its 36 pin header for asynchronous serial I/O. The interface conforms to standard RS-232. The signals in the asynchronous serial interface are described below: DCD Data Carrier Detect - Output from Module - When asserted (positive voltage), DCD informs the DTE that a communications link has been TM established with another CompactRF . Modem (DCE) Host Microprocessor Signal (DTE) ← ← ← DCD RX TX DTR SG DSR RTS CTS → IN → IN OUT OUT → IN → IN OUT → IN Arrows denote the direction that signals are asserted (e.g., DCD originates at the DCE and tells the DTE that a carrier is present). RXD Receive Data - Output from Module - Signals transferred from the TM CompactRF are received by the DTE via RX. TXD Transmit Data - Input to Module - Signals are transmitted from the DTE TM via TX to the CompactRF . DTR Data Terminal Ready - Input to Module - Asserted by the DTE to inform the modem that it is alive and ready for communications. SG Signal Ground - Provides a ground reference for all signals transmitted by both DTE and DCE. DSR Data Set Ready - Output from Module - Asserted by the DCE to inform the DTE that it is alive and ready for communications. DSR is the modem’s equivalent of the DTR signal. RTS Request to Send - Input to Module - A “handshaking” signal which is asserted by the DTE when it is ready. When hardware handshaking is used, the RTS signal indicates to the DCE that the host can receive data. CTS Clear to Send - Output from Module - A “handshaking” signal which is asserted by the DCE when it has enabled communications and transmission from the DTE can commence. When hardware handshaking is used, the CTS signal indicates to the host that the DCE can receive data. Notes: It is typical to refer to RXD and TXD from the perspective of the DTE. This should be kept in mind when looking at signals relative to the modem (DCE); the modem transmits data on the RXD line, and receives on TXD. “DCE” and “modem” are often synonymous since a modem is typically a DCE device. “DTE” is, in most applications, a device such as a host microprocessor. CompactRF TM Operating Manual: Serial Interface 43 44 CompactRF TM Operating Manual: Appendix B Serial Interface C. Factory Default Settings AT&F1 - Master Default Settings AT&F3 - Repeater Default Settings E1, Q0, V1, W0, S0=0, S2=43, S3=13, S4=10, S5=8 E1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8 DCD DTR Framing Handshaking DSR Operating Mode Serial Baud Rate Wireless Link Rate Network Address Unit Address Primary Hop Pattern Encryption Key Output Power Hop Interval Data Format Packet Minimum Size Packet Maximum Size Packet Retransmissions Link Handshaking Packet Repeat Interval Character Timeout (ms) Modbus Mode RTS/DCD Framing (ms) DCD Timeout (ms) Secondary Hop Pattern Packet Retry Limit DCD DTR Framing Handshaking DSR Operating Mode Serial Baud Rate Wireless Link Rate Network Address Unit Address Primary Hop Pattern Encryption Key Output Power Hop Interval Data Format Packet Minimum Size Packet Maximum Size Packet Retransmissions Link Handshaking Packet Repeat Interval Character Timeout (ms) Modbus Mode RTS/DCD Framing (ms) DCD Timeout (ms) Secondary Hop Pattern Packet Retry Limit &C1 (On) &D0 (DTR is ignored) &E0 (Disabled) &K3 (Enabled) &S1 (On in Data, Off in Command) S101=1 (Master P-MP) S102=1 (115kbaud) S103=4 (Fast, FEC) S104=1 S105=1 S106=0 S107=1 S108=2 (100mW) S109=8 S110=1 (8N1) S111=1 S112=255 S113=2 S122=1 (Enabled) S115=1 (Don’t Care) S116=8 S117=0 S120=0 S121=0 S206=2 (Don’t Care) S213=2 (Don’t Care) &C1 (On when modems are synced) &D0 (DTR is ignored) &E0 (Disabled) &K3 (Enabled) &S1 (On in Data, Off in Command) S101=4 (Repeater) S102=1 (115kbaud) S103=4 (Fast, FEC) (Set by Master) S104=1 S105=3 S106=0 S107=1 S108=2 (100mW) S109=8 (Set by Master) S110=1 (8N1) S111=1 (Set by Master) S112=255 (Set by Master) S113=2 S122=1 (Enabled) (Set by Master) S115=1 S116=8 S117=0 S120=0 S121=0 S206=2 S213=2 AT&F2 - Slave Default Settings AT&F4 -Slave Through Repeater Default Settings E1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8 E1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8 DCD DTR Framing Handshaking DSR Operating Mode Serial Baud Rate Wireless Link Rate Network Address Unit Address Primary Hop Pattern Encryption Key Output Power Hop Interval Data Format Packet Minimum Size Packet Maximum Size Packet Retransmissions Link Handshaking Packet Repeat Interval Character Timeout (ms) Modbus Mode RTS/DCD Framing (ms) DCD Timeout (ms) Secondary Hop Pattern Packet Retry Limit DCD DTR Framing Handshaking DSR Operating Mode Serial Baud Rate Wireless Link Rate Network Address Unit Address Primary Hop Pattern Encryption Key Output Power Hop Interval Data Format Packet Minimum Size Packet Maximum Size Packet Retransmissions Link Handshaking Packet Repeat Interval Character Timeout (ms) Modbus Mode RTS/DCD Framing (ms) DCD Timeout (ms) Secondary Hop Pattern Packet Retry Limit CompactRF TM &C1 (On when modems are synced) &D0 (DTR is ignored) &E0 (Disabled) &K3 (Enabled) &S1 (On in Data, Off in Command) S101=3 (Slave) S102=1 (115kbaud) S103=4 (Fast, FEC) (Set by Master) S104=1 S105=2 S106=0 S107=1 S108=2 (100mW) S109=8 (Set by Master) S110=1 (8N1) S111=1 (Set by Master) S112=255 (Set by Master) S113=2 (Don’t Care) S122=1 (Enabled) (Set by Master) S115=1 S116=9 S117=0 S120=0 S121=0 S206=2 (Don’t Care) S213=2 Operating Manual: Appendix C. Factory Default Settings &C1 (On when modems are synced) &D0 (DTR is ignored) &E0 (Disabled) &K3 (Enabled) &S1 (On in Data, Off in Command) S101=3 (Slave) S102=1 (115kbaud) S103=4 (Fast, FEC) (Set by Master) S104=1 S105=4 S106=2 S107=1 S108=2 (100mW) S109=8 (Set by Master) S110=1 (8N1) S111=1 (Set by Master) S112=255 (Set by Master) S113=2 (Don’t Care) S122=1 (Enabled) (Set by Master) S115=1 S116=8 S117=0 S120=0 S121=0 S206=2 (Don’t Care) S213=2 45 46 CompactRF TM Operating Manual: Appendix C Factory Default Settings D. Performance Tables The scope of this appendix is to find the best possible performance and maximum packet size at different modes of operation. The setup assumes a baud rate of 115k, no retries and no retransmissions.. Master to Slave Communication. (No Repeater) Link Rate = Fast NO FEC Master to Slave Communication. (No Repeater) Link Rate = Fast WITH FEC Master to Repeater Direct Communication. Link Rate = Fast NO FEC Master to Repeater Direct Communication. Link Rate = Fast WITH FEC Master to Slave Through One or More Repeaters. Link Rate = Fast NO FEC Master to Slave Through One or More Repeaters. Link Rate = Fast WITH FEC CompactRF TM Hop Interval 1 (8 ms) 2 (12 ms) 3 (16 ms) 4 (20 ms) 5 (30 ms) 6 (45 ms) 7 (80 ms) 8 (120 ms) 1 (8 ms) 2 (12 ms) 3 (16 ms) 4 (20 ms) 5 (30 ms) 6 (45 ms) 7 (80 ms) 8 (120 ms) 1 (8 ms) 2 (12 ms) 3 (16 ms) 4 (20 ms) 5 (30 ms) 6 (45 ms) 7 (80 ms) 8 (120 ms) 1 (8 ms) 2 (12 ms) 3 (16 ms) 4 (20 ms) 5 (30 ms) 6 (45 ms) 7 (80 ms) 8 (120 ms) 1 (8 ms) 2 (12 ms) 3 (16 ms) 4 (20 ms) 5 (30 ms) 6 (45 ms) 7 (80 ms) 8 (120 ms) 1 (8 ms) 2 (12 ms) 3 (16 ms) 4 (20 ms) 5 (30 ms) 6 (45 ms) 7 (80 ms) 8 (120 ms) Optimal Packet Size (bytes) 14 66 110 154 255 255 255 255 34 54 76 130 210 255 255 N/A 22 44 101 178 255 255 N/A N/A 16 43 80 174 255 N/A 22 43 93 174 255 255 N/A N/A N/A 14 40 80 Throughput (kbps)* 20 52 66 74 83 56 31 21 22 28 32 38 43 30 20 N/A 13 21 32 39 31 21 N/A N/A 12 16 20 20 N/A 13 21 31 38 31 21 N/A N/A N/A 12 16 174 255 19 20 Operating Manual: Appendix D. Performance Tables 47 48 CompactRF TM Operating Manual: Appendix D. Performance Tables 50 CompactRF TM Operating Manual: F. Technical Specifications Electrical/Physical Data Interface Asynchronous Serial Port, TTL Levels Signals Sig. Gnd, TX, RX, DCD, DSR, DTR, RTS, CTS Baud rate 2,400 - 19200 bps, (user-selectable) Up to 19200 full-duplex sustained throughput Communications Range1 16 kilometres (10 miles) Voltage Requirements 4.75 to 5.5 VDC, 1.0 Amp Current Consumption Rx: 85mA; Tx 1mW: 100mA; Tx 10mW: 132mA; Tx 100mW: 231mA; Tx 1W: 600mA; Sleep: <1.5mA Operating Frequency 902 - 928 MHz System Gain 133 dB Sensitivity -103 dBm Output Power 1mW, 10mW, 100mW, 1W (user-selectable) Spreading Code Frequency Hopping Hopping Patterns 35 pseudo-random, user-selectable Error Detection CRC-16 with auto re-transmit Memory Dimensions (LxWxH) Non-volatile configuration memory Approx. 2.0” x 1.5” x 0.375” Weight Approx. 20 grams Operating Environment Temperature: -25 to +70°C Humidity: 5 to 95%, non-condensing Storage Temperature -40 to 90°C 1. Clear line-of-sight, elevated antennas. CompactRF TM Operating Manual: Appendix F. Technical Specifications 51 52 CompactRF TM Operating Manual: Appendix F. Technical Specifications G. Development Board Schematics Schematics begin on next page. CompactRF TM Operating Manual: Appendix G. Development Board Schematics 53 54 CompactRF TM Operating Manual: Appendix G. Development Board Schematics CompactRF TM Operating Manual: Appendix G. Development Board Schematics 55 56 CompactRF TM Operating Manual: Appendix G. Development Board Schematics CompactRF TM Operating Manual: Appendix G. Development Board Schematics 57 58 CompactRF TM Operating Manual: Appendix H. Mechanical Drawing H. Mechanical Drawing 1500 375 19 18 75 330 Top View 2000 78.7 (2mm) Pin 1 36 Dimensions in thousandths of an inch. Shaded areas = keep clear. 80 525 dia. 64 410 200 225 Recommended Footprint Drill Size = 32 mil 18 19 78.7 (2mm) 1245 Microhard Systems Inc. Document Number: D1043-02 36 1245 500 Sheet 1 of 1 Rev. 110, 1144 - 29th Avenue N.E.. Calgary, Alberta, Canada T2E 7P1 Drawn By: NB CompactRF Mechanical Drawing Size A Wednesday, July 26, 2000 59 Operating Manual: Appendix H. Mechanical Drawing TM CompactRF 60 CompactRF TM Operating Manual: Appendix H. Mechanical Drawing I. Glossary Terminology Used in the CompactRFTM Operating Manual Asynchronous communications A method of telecommunications in which units of single bytes of data are sent separately and at an arbitrary time (not periodically or referenced to a clock). Bytes are “padded” with start and stop bits to distinguish each as a unit for the receiving end, which need not be synchronized with the sending terminal. Attenuation The loss of signal power through equipment, lines/cables, or other transmission devices. Measured in decibels (dB). Bandwidth The information-carrying capacity of a data transmission medium or device, usually expressed in bits/second (bps). Baud Unit of signaling speed equivalent to the number of discrete conditions or events per second. If each signal event represents only one bit condition, then baud rate equals bits per second (bps) – this is generally true of the serial data port, so baud and bps have been used interchangeably in this manual when referring to the serial port; this is not always the case during the DCE-to-DCE communications, where a number of modulation techniques are used to increase the bps rate over the baud rate. Bit The smallest unit of information in a binary system, represented by either a 1 or 0. Abbreviated “b”. Bits per second (b/s or bps) A measure of data transmission rate in serial communications. Also see baud. Byte A group of bits, generally 8 bits in length. A byte typically represents a character of data. Abbreviated “B”. Characters per second (cps) A measure of data transmission rate for common exchanges of data. A character is usually represented by 10 bits: an 8bit byte plus two additional bits for marking the start and stop. Thus, in most cases (but not always), cps is related to bits per second (bps) by a 1:10 ratio. CRC (Cyclic Redundancy Check) An error-detection scheme for transmitted data. Performed by using a polynomial algorithm on data, and appending a checksum to the end of the packet. At the CompactRF TM Operating Manual: Appendix I. Glossary receiving end, a similar algorithm is performed and checked against the transmitted checksum. Crossover cable (Also known as rollover, null- modem, or modem-eliminator cable) A cable which allows direct DTE-to-DTE connection without intermediate DCEs typically used to bridge the two communicating devices. Can also be used to make cabled DCE-to-DCE connections. The name is derived from “crossing” or “rolling” several lines, including the TX and RX lines so that transmitted data from one DTE is received on the RX pin of the other DTE and vice-versa. Data Communications Equipment (DCE, also referred to as Data Circuit-Terminating Equipment, Data Set) A device which facilitates a communications connection between Data Terminal Equipment (DTEs). Often, two or more compatible DCE devices are used to “bridge” DTEs which need to exchange data. A DCE performs signal encoding, decoding, and conversion of data sent/received by the DTE, and transmits/receives data with another DCE. Common example is a modem. Data Terminal Equipment (DTE) An enddevice which sends/receives data to/from a DCE, often providing a user-interface for information exchange. Common examples are computers, terminals, and printers. dBm Stands for “Decibels referenced to one milliwatt (1 mW)”. A standard unit of power level commonly used in RF and communications (n/10) work. n dBm is equal to 10 milliwatt, so 0dBm = 1mW, -10dBm = 0.1mW, -20dBm = 0.01mW, etc. DCE See Data Communications Equipment. DTE See Data Terminal Equipment. Flow Control A method of moderating the transmission of data so that all devices within the communications link (DTEs and DCEs) transmit and receive only as much data as they can handle at once. This prevents devices from sending data which cannot be received at the other end due to conditions such as a full buffer or hardware not in a ready state. This is ideally handled by hardware using flow-control and handshaking signals, but 61 can be controlled also by software using X-ON/XOFF (transmitter on/off) commands. Frequency-hopping A type of spread spectrum communication whereby the carrier frequency used between transmitter and receiver changes repeatedly in a synchronized fashion according to a specified algorithm or table. This minimizes unauthorized jamming (interference) and interception of telecommunications. Full-duplex Where data can be transmitted, simultaneously and independently, bidirectionally. Half duplex Exists when the communications medium supports bi-directional transmission, but data can only travel in one direction at the same time. Handshaking A flow-control procedure for establishing data communications whereby devices indicate that data is to be sent and await appropriate signals that allow them to proceed. Line-of-sight Condition in which a transmitted signal can reach its destination by travelling a straight path, without being absorbed and/or bounced by objects in its path. Master The station which controls and/or polls one or more Slave stations in a point-to-point or pointto-multipoint network. Often functions as a server or hub for the network. Non-volatile memory Memory which retains information which is written to it. Null modem cable See Crossover cable. Point-to-point A simple communications network in which only two DTEs are participants. Point-to-multipoint A communications network in which a Master DTE communicates with two or more Slave DTEs. Repeater A device which automatically amplifies or restores signals to compensate for distortion and/or attenuation prior to retransmission. A repeater is typically used to extend the distance for which data can be reliably transmitted using a particular medium or communications device. many newer devices use a compact 9-pin connector with only the essential signaling lines used in asynchronous serial communications. Lines have two possible states: “high” (on, active, asserted, carrying +3 to +25 V) or “low” (off, inactive, disasserted, carrying -3 to -25 V). RTU (Remote Terminal Unit) A common term describing a DTE device which is part of a widearea network. Often a RTU performs data I/O and transmits the data to a centralized station. Serial communications A common mode of data transmission whereby character bits are sent sequentially, one at a time, using the same signaling line. Contrast with parallel communications where all bits of a byte are transmitted at once, usually requiring a signal line for each bit. Shielded cable Interface medium which is internally shrouded by a protective sheath to minimize external electromagnetic interference (“noise”). Slave A station which is controlled and/or polled by the Master station for communications. Typically represents one end of a point-to-point connection, or one of the terminal nodes in a point-tomultipoint network. Often a RTU is linked by a Slave DCE. Spread spectrum A method of transmitting a signal over a wider bandwidth (using several frequencies) than the minimum necessary for the originally narrowband signal. A number of techniques are used to achieve spread spectrum telecommunications, including frequency hopping. Spread spectrum provides the possibility of sharing the same band amongst many users while increasing the tolerance to interference and noise, and enhancing privacy of communications. Throughput A measure of the rate of data trans- mission passing through a data communication system, often expressed as bits or characters per second (bps or cps). RS-232 (Recommended Standard 232; more accurately, RS-232C or EIA/TIA-232E) Defined by the EIA, a widely known standard electrical and physical interface for linking DCEs and DTEs for serial data communications. Traditionally specifies a 25-pin D-sub connector, although 62 CompactRFTM Operating Manual: Appendix I. Glossary
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