Microhard Systems 00P3 900 MHz Spread Spectrum Module User Manual CompactRFMAN

Microhard Systems Inc 900 MHz Spread Spectrum Module CompactRFMAN

COMPACTRF Manual

Operating ManualCompactRFTMOEM Spread Spectrum TransceiverRevision 1.01, January 3, 2001Microhard Systems Inc.#110, 1144 - 29th Ave. N.E.Calgary, Alberta T2E 7P1Phone: (403) 248-0028Fax: (403) 248-2762www.microhardcorp.com
ii CompactRFTM Operating ManualCompactRFTM900 MHzOEM Spread SpectrumTransceiverFCC RF Exposure WarningIn order to comply with the FCC/ICadopted RF exposure requirements, thistransmitter system will be installed by themanufacturer’s reseller professional.Installation of all antennas must beperformed in a manner that will provide atleast 23 cm clearance from the frontradiating aperture, to any user or memberof the public.This manual contains information of proprietary interest toMicrohard Systems Inc. It has been supplied in confidence topurchasers and users of the CompactRF, and by accepting thismaterial the recipient agrees that the contents will not be copiedor reproduced, in whole or in part, without prior written consentof Microhard Systems Inc.Microhard Systems Inc. has made every effort to assure that thisdocument is accurate and complete. However, the companyreserves the right to make changes or enhancements to themanual and/or the product described herein at any time andwithout notice. Furthermore, Microhard Systems Inc. assumesno liability resulting from any omissions in this document, orout 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 inapplications where failure could result in damage to property orhuman injury or loss of life.The electronic equipment described in this manual generates,uses, and radiates radio frequency energy. Operation of thisequipment in a residential area may cause radio interference, inwhich case the user, at his own expense, will be required to takewhatever measures necessary to correct the interference.FCC Declaration of ConformityThis device complies with Part 15 of the FCC Rules.Operation is subject to the following two conditions: (1) thisdevice may not cause harmful interference, and (2) thisdevice must accept any interference received includinginterference that may caused undesired operation.Microhard Systems Inc.’s products are warranted against allfailures which occur as a result of defective material orworkmanship within 12 months of purchase by the user. Thiswarranty does not extend to products that, in the opinion ofMicrohard Systems Inc., have been subject to misuse, accidents,lightning strikes, improper installation or application, nor shallit extend to units which have, in Microhard Systems Inc.’sopinion, been opened, tampered with or repaired by anunauthorized facility.Microhard Systems Inc.Leaders in Wireless Telecom#110, 1144 - 29th Ave. N.E.Calgary, Alberta T2E 7P1Phone: (403) 248-0028Fax: (403) 248-2762www.microhardcorp.com© 2001 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 registeredtrademarks of their respective holders.Manual Revision 1.01, January 3, 2001.
iii CompactRFTM Operating ManualContents1. Introduction1.0 Product Overview .............................................................................................................................................................................. 11.1 Features.............................................................................................................................................................................................. 11.2 About this Manual ............................................................................................................................................................................. 21.3 Unpacking and Inspection ................................................................................................................................................................. 32. Electrical/Physical2.0 Functional Block Diagram................................................................................................................................................................. 52.1 Pinout................................................................................................................................................................................................. 62.2 DC Characteristics............................................................................................................................................................................. 82.3 AC Characteristics.............................................................................................................................................................................. 93. Mode of Operation3.1 Data Mode ....................................................................................................................................................................................... 113.2 Command Mode .............................................................................................................................................................................. 123.2.1 Menu Interface......................................................................................................................................................................... 133.2.2 AT Command Interface........................................................................................................................................................... 133.3 Switching Between Command and Data Modes.............................................................................................................................. 143.3.1 Switching Between AT Command Interface and Data Mode................................................................................................... 143.3.2 Switching Menu Interface and Data Mode.............................................................................................................................. 153.4 Sleep Mode...................................................................................................................................................................................... 154. Configuration4.1 Quick Start Approach ...................................................................................................................................................................... 174.2 AT Commands................................................................................................................................................................................. 184.3 AT Registers .................................................................................................................................................................................... 214.4 Configuration Settings..................................................................................................................................................................... 22S Register 101 - Operating Mode..................................................................................................................................................... 23S Register 102 - Serial Baud Rate.................................................................................................................................................... 25S Register 104 - Network Address................................................................................................................................................... 26S Register 105 - Unit Address.......................................................................................................................................................... 26S Registers 106 and 206 - Primary and Secondary Hopping Patterns.............................................................................................. 26S Register 107 - Encryption Key...................................................................................................................................................... 28S Register 108 - Output Power Level............................................................................................................................................... 28S Register 109 - Hopping Interval.................................................................................................................................................... 29S Register 110 - Data Format............................................................................................................................................................ 29S Registers 111 and 112 - Packet Minimum and Maximum Size..................................................................................................... 30S Register 116 - Packet Character Timeout ...................................................................................................................................... 30S Registers 113 and 213 - Packet Retransmission/Packet Retry Limit ............................................................................................. 31S Register 115 - Packet Repeat Interval........................................................................................................................................... 31S Register 122 - Link Handshaking.................................................................................................................................................. 32S Register 117 - Modbus Mode ........................................................................................................................................................ 32S Register 120 and 121- RTS/DCD Framing/Timeout ..................................................................................................................... 33S Register 123 - RSSI Reading......................................................................................................................................................... 335. Installation5.1 Estimating the Gain Margin............................................................................................................................................................. 355.2 Antennas and Cabling...................................................................................................................................................................... 375.2.1 Internal Cabling ....................................................................................................................................................................... 375.2.2 Installing External Cables, Antennas and Lightning Arrestors................................................................................................ 38A. Modem Command Summary...................................................................................................................................................................... 41B. Serial Interface............................................................................................................................................................................................ 43C. Factory Default Settings.............................................................................................................................................................................. 45DPerformance Tables...................................................................................................................................................................................... 47E. Hopping Tables............................................................................................................................................................................................ 49F. Technical Specifications............................................................................................................................................................................. 51G. Development Board Schematics ................................................................................................................................................................. 53H. Mechanical Drawing................................................................................................................................................................................... 59I. Glossary ...................................................................................................................................................................................................... 61J. FCC RF Exposure........................................................................................................................................................................................ 63
iv CompactRFTM Operating Manual
CompactRFTM Operating Manual: Chapter 1 Introduction. 11. Introduction1.0 Product OverviewThe CompactRFTM is a high-performance embedded wireless datatransceiver. Operating in the 902-928 MHz ISM band, this frequency-hopping spread-spectrum module is capable of providing reliable wirelessdata transfer between almost any type of equipment which uses anasynchronous serial interface. The small-size and low operating current ofthis module make it ideal for mobile and battery powered applications.Typical uses for this module include:n Automated Meter Reading (AMR);n Vending Machines;n Point of Sale Devices;n Fleet Management;n Telemetry;n Remote Camera/Robot Control;n Security Systems; and,n Display Signs.While a pair of CompactRFTM modules can link two terminal devices (“point-to-point” operation), multiple modules can be used together to create anetwork of various topologies, including “point-to-multipoint” and “repeater”operation. Multiple independent networks can operate concurrently, so it ispossible for unrelated communications to take place in the same or a nearbyarea without sacrificing privacy or reliability.1.1 FeaturesKey features of the CompactRFTM include:ntransmission within a public, license-exempt band of the radiospectrum1 – this means that it can be used without access fees(such as those incurred by cellular airtime);na serial I/O data port with handshaking and hardware flowcontrol, allowing the CompactRFTM to interface directly to anyequipment with an asynchronous serial interface. 1902-928 MHz, which is license-free within North America; may need to be factory-configureddifferently for some countries.
2CompactRFTM Operating Manual: Chapter 1 Introductionn30 sets of user-selectable pseudo-random hopping patterns,intelligently designed to offer the possibility of separatelyoperating multiple networks while providing security, reliabilityand high tolerance to interference;nencryption key with 65536 user-selectable values to maximizesecurity and privacy of communications;nbuilt-in CRC-16 error detection and auto re-transmit to provide100% accuracy and reliability of data;nease of installation and use – the CompactRFTM gives the userthe choice of a menu interface, or a subset of standard AT stylecommands, very similar to those used by traditional telephoneline modems.While the typical application for the CompactRFTM is to provide a short- tomid-range wireless communications link between DTEs, it can be adapted toalmost any situation where an asynchronous serial interface is used and dataintercommunication is required.1.2 About this ManualThis manual has been provided as a guide and reference for installing andusing CompactRFTM wireless transceivers. The manual contains instructions,suggestions, and information which will help you set up and achieve optimalperformance from your equipment using the CompactRFTM.It is assumed that users of the CompactRFTM have either system integration orsystem design experience. Chapter 2 details the physical/electricalcharacteristics of the module. Chapter 3 gives an overview of the modes ofoperation. Chapter 4 describes the AT command register/menu setup andconfiguration. Chapter 5 is an installation/deployment guide. TheAppendices, including the Glossary of Terms, are provided as informationalreferences which you may find useful throughout the use of this manual aswell as during the operation of the product.Throughout the manual, you will encounter not only illustrations that furtherelaborate on the accompanying text, but also several symbols which youshould be attentive to:Caution or Warning: Usually advises against some action which couldresult in undesired or detrimental consequences.Point to Remember: Highlights a key feature, point, or step which is worthnoting, Keeping these in mind will make using the CompactRF moreuseful or easier to use.Tip: An idea or suggestion is provided to improve efficiency or to makesomething more useful.With that in mind, enjoy extending the boundaries of your communicationswith the CompactRFTM.
CompactRFTM Operating Manual: Chapter 1 Introduction. 31.3 Unpacking and InspectionThe following items should be found in the shipping carton. Inspect thecontents for any shipping damage. Report damages or shortages to thedistributor from which the unit was purchased. Keep all packing materials inthe event that transportation is required in the future.Package contents for the CompactRF development kit (normal distribution):1CompactRFTM Wireless Module 22Operating Manual (this document) 1312V Wall Adapter 24DB9 Straight-through Serial Cable 25Rubber Duck Antenna 26CompactRFTM Development Board 2
4CompactRFTM Operating Manual: Chapter 1 Introduction
CompactRFTM Operating Manual: Chapter 2 Electrical/Physical 52. Electrical/Physical2.0 Functional Block DiagramAntennaSwitchMixerLNAMixerIF DemodFrequencySynthesizerPAComparator+-uC8 bit data busUART(DCE)GAINA/D SRAM EEPROMSRAMCTSDCDDSRRxDDTRTxDRTSARSSI\Sleep\Config\ResetRSSI1-3SYNCRXMODETXMODEDVccAVccGND
6CompactRFTM Operating Manual: Chapter 2 Electrical/Physical2.1 PinoutFigure 1 provides a top-view pinout drawing of the CompactRF module. Thecorner pins (1,18,19,36) are labeled directly on the module.123456789101112131415161718363534333231302928272625242322212019NCNCNCNC\ConfigSYNCRSSI1RSSI2RSSI3Rx ModeTx ModePGMGNDGNDGNDGNDGNDAVccAVccGNDARSSINCNC\ResetDVccGNDTxDRxDGNDDSRCTSDCDRTSDTRSCK\SleepCompactRF900MHzTMFigure 1 - Pinout (Top View)Pin Name No. Description I/OARSSI 34 Provides an analog level of the received signalstrength. This is an uncalibrated signal, and willprovide only rough measurements of signalstrength.OAVcc 18,36 Positive Supply for Radio Circuitry. See Section2.1 for DC Characteristics\Config 5Momentarily assert low to enter configurationmode. See Section 2.2 ICTS 24 RS-232 Clear to Send. Active low (TTL level)output. See Appendix B for a complete descriptionof all RS-232 signals.ODCD 23 RS-232 Data Carrier Detect. Active low (TTLlevel) output. ODSR 25 RS-232 Data Set Ready. Active low (TTL level)output.O
CompactRFTM Operating Manual: Chapter 2 Electrical/Physical 7Pin Name No. Description I/ODTR 21 RS-232 Data Terminal Ready. Active low(TTL level) input.IDVcc 30 Positive Supply for Logic circuitry and I/Opins. See Section 2.2 for DC CharacteristicsGND 13-1726,29,35Ground reference for logic, radio and I/O pins.PGM 12 Programming Status indicator. This output isfor factory use only, and should normally beleft disconnected.O\Reset 31 Active low reset input to the module. SeeSection 2.3 for timing information.ISYNC 6Active high output indicates the modem issynchronized with at least one other modemORSSI1 7Receive Signal Strength Indicator 1. Thisoutput is the first of the three RSSI indicatorsto become active high as the signal strengthincreases. See Table 2 for detailsORSSI2 8Receive Signal Strength Indicator 2. Thisoutput is the second RSSI indicator to becomeactive high as the signal strength increases.See Table 2 for details.ORSSI3 9Receive Signal Strength Indicator 3. Thisoutput is the last RSSI indicator to becomeactive high as the signal strength increases.See Table 3 for details.ORTS 22 RS-232 Request to Send. Active low (TTLlevel) input.IRxD 27 RS-232 Receive Data. TTL level output. ORXMODE 10 Active high output indicates module isreceiving data over the RF channel.OSCK 20 ISP Programming Clock. Used in conjunctionwith RxD and TxD when upgrading theFLASH-based firmware.ITxD 28 RS-232 Transmit Data. TTL level input. ITXMODE 11 Active high output indicates module istransmitting data over the RF channel.O\Sleep 19 Assert low to put the unit to sleep. SeeSection 2.3 for timing information.INC 1-4,32,33 No Connect
8CompactRFTM Operating Manual: Chapter 2 Electrical/PhysicalFor detailed mechanical drawings, refer to Appendix H2.2 DC CharacteristicsSym Characteristic Min Typ Max UnitsAVCC Radio Supply Voltage 4.9 5.0 5.5 VDVCC Logic Supply Voltage 4.75 5.0 5.5 VVPOT Power On Reset Threshold Voltage 1.8 22.2 VVRST Reset Pin Threshold Voltage DVCC/2VAICCR Radio Supply Current in Receive Mode 54 60 66 mAAICCT0Radio Supply Current at 1mW Transmit 68 75 82 mAAICCT1Radio Supply Current at 10mW Transmit 96 107 118 mAAICCT2Radio Supply Current at 100mW Transmit 185 206 227 mAAICCT3Radio Supply Current at 1W Transmit 517 575 633 mAAISL Radio Sleep Current 500 uADICC Logic Supply Current 22 25 28 mADISL Logic Sleep Current 1.0 mAVIL Input Low Voltage (Pins 5,19,21,22,28) -0.5 .3DVCC VVIH Input High Voltage (Pins 5,19,21,22,28) 0.6VCC VCC+.5 VVOL Output Low Voltage (Pins 6-11,23-25,27) 0.6 VVOH Output High Voltage(Pins 6-11,23-25,27) 4.2 VISRCE Sourcing Current (Pins 6-11,23-25,27) PerPin 10 mA
CompactRFTM Operating Manual: Chapter 2 Electrical/Physical 92.3 AC CharacteristicsSym Characteristic Min Typ Max UnitsTTOUT Reset Delay Time-Out Period 12.8 16.0 19.2 msTCFG \Config. pulse duration See Note msTS2SD \Sleep low to internal sleep delay 0See Note msTSN Snooze duration 10 msTSNIFF Sniff duration 100 usTWDLY \Sleep high to internal wakeup 0TSN msNote: 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 \Resetline operation. A fixed internal reset delay timer of roughly 16ms is triggeredas the VPOT or VRST threshold is reached.TVVDV\ResetInternal ResetCCTOUTRSTPOTFigure 2. Reset TimingFigure 3 illustrates the sleep operation for the CompactRF. When the \Sleepline 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 \Sleepline has again gone high. If the \Sleep line is low, the modem goes back tosleep. If it is high, the modem wakes up and resumes normal operation.\Sleep\Internal Sleep TSNIFFTS2SDTSNTWDLYFigure 3. Sleep/Wakeup Timing
10 CompactRFTM Operating Manual: Chapter 2 Electrical/Physical
CompactRFTM Operating Manual: Chapter 3 Modes of Operation 113. Modes of OperationThe CompactRFTM modem can be easily configured to meet a wide range ofneeds and applications. The module is designed such that allcommunication 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 datathat 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. Whenoperating 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 ofoperation called sleep mode. The module will always be in one of thesethree modes.3.1 Data ModeData mode is the normal operating mode of the CompactRF. When in datamode, the CompactRF is communicating with other CompactRF modules,and facilitating wireless asynchronous serial communication amongst two ormore terminal devices. There are three basic elements to any CompactRFcommunications network:• One module configured as the Master• Zero or more modules configured as Repeaters• One or more modules configured as SlavesThe function of the Master is to provide synchronization for the entirenetwork, and to control the flow of data. There is always one Master pernetwork. The Master is the ultimate destination for all data collected at thevarious Repeater’s and Slave’s serial ports. With the network set up forPoint-to-Multipoint communication, all data received at the Master’s serialport is transmitted to every Repeater and Slave in the network. TheCompactRF is a frequency hopping transceiver, meaning that it “hops” to anew frequency after a predetermined time interval. This time interval is afixed time set by the user, and can range from 14ms to 180ms. TheCompactRF hops according to a pseudorandom pattern of 50 differentchannels.
12 CompactRFTM Operating Manual: Chapter 3 Modes of OperationMSNetwork 1MSRMSRNetwork 2MSSSNetwork 3MRSSSNetwork 4MRSRSNetwork 5Figure 4 - Sample NetworkTopologies. Virtually anyCombination of Slaves andRepeaters May be Used.When configured as a Slave, the CompactRF searches for synchronizationwith a Master. Network topologies consisting of a single Master andvirtually any combination of Slaves and Repeaters may be deployed. Thefunctionality of any particular CompactRFTM can be configured as follows:nMaster Point-to-Point: The modem is configured tocommunicate with a single Slave, either directly, or through oneor more Repeaters.nMaster Point-to-Multipoint: The modem is configured tocommunicate with one or more Slaves and/or Repeaters.nSlave: The modem is configured to communicate with oneMaster either directly or through one or more Repeaters..nRepeater: The modem is configured to pass information fromeither a Master or another Repeater onto subsequent Repeatersand/or Slaves and vice versa. The Repeater also acts as a Slavein the sense that, like a Slave, it passes information to/from itsserial port.Examples of different network topologies are shown in Figure 4. Network1 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 noRepeaters. Networks 4 and 5 gives examples of Point-to-Multipointnetworks consisting of both Repeaters and Slaves. There is effectively norestriction to the number of Repeaters and Slaves that can be added to anetwork. As seen in Network 4, a Master can communicate directly withboth Slaves and Repeaters.3.2 Command ModeThe CompactRF firmware has been designed to allow the user to selectbetween two different Command Mode interfaces: Menu Interface; or, ATCommand Interface. The menu interface is ideal for applications whichinvolve human configuration of the operating parameters of the modem.The AT Command interface is more suited for direct interface with anothermicrocontroller or for higher level Windows-based software applications.The CompactRF development board is a useful tool for familiarizingyourself with the various operating parameters and user interface.Reference schematics for the development board can be found in AppendixG. To access the CompactRF’s command mode using the developmentboard:1. Insert the module into the socket with the antenna connector towardsthe edge of the board.2. Attach the supplied antenna.3. Connect a straight through serial cable between the DB9 connector andthe serial port on your PC4. Apply power to the development board5. Run any terminal application program such as Hyperterminal6. Set the serial port to 9600 baud, 8N17. Momentarily press the configure (CFG) button
CompactRFTM Operating Manual: Chapter 3 Modes of Operation 13Menu selections areimmediately stored to themodule’s non-volatilememory.3.2.1 Menu InterfaceAt this point, you should see a menu similar to the following appear:Microhard Systems Inc CompactRF Configuration1) Operating Mode S101=1 MasterPP 2) Serial Baud Rate S102=4 96003) Network Address S104=255 4) Unit Address S105=655355) Hopping Pattern S106=0 6) Encryption Key S107=655357) Output Power Level S108=0 1 mW 8) Retry Limit S213=2559) Hop Interval S109=20 x 0.74 ms = 14 msD) Autoanswer S0=1 E) Interface S6=0 AT styleA) Handshaking &K3 Enabled N) DTR &D0 IgnoredO) DSR &S0 ON in Data Mode M) DCD &C1 ON when sync'd S2=43 S3=13 S4=10 S5=8Type AT for AT interface or hit Enter for menuYou now have the option of choosing between the menu interface, or the ATCommand 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, tochange the unit’s Operating Mode, press the 1 key. The following sub-menuwill appear:Operating Mode* 1) MasterPP 2) SlavePPESC to exitSelect Operating Mode :The instant a selection is made, it is immediately stored into the module’snon-volatile memory.3.2.2 AT Command InterfaceThe CompactRF may also be controlled through an AT Command lineinterface, using a command set which is very similar to a traditional Hayestelephone modem command set.For AT Command operation, instead of hitting ENTER at the prompt, typeAT <ENTER>. The characters ‘AT’ are known as the attention charactersand must be typed at the beginning of each command line. The modemshould respond with OK. Illustrating the same example as above toconfigure the Operating Mode using AT Commands, type the following:ATS101=2 <ENTER>The modem should respond with ’OK.’ The above command will set theoperating mode to SlavePP (Slave Point to Point).
14 CompactRFTM Operating Manual: Chapter 3 Modes of OperationWhen using AT Commands,use the &W command tostore the most currentsettings to memory.With AT Commands, the settings are not immediately stored to non-volatilememory, therefore if the modem is powered down at this point, theOperating Mode would revert to its previous value. To store any recentlyupdated command registers, the following “write” command must beentered.AT&W <ENTER>3.3 Switching Between Command and Data ModesThe method for switching between data and command modes depends onwhich interface you are using (Menu or AT). There is a parameter called“Interface” (Menu item E) which defines whether the modem is currentlyoperating in AT mode or Menu mode.3.3.1 Switching Between AT Command Interface and DataModeYour modem must be in Command Mode for it to execute a command. Ifyou send characters when the modem is in Data Mode, the modem transmitsthe characters over the air.Depending on its settings, the modem will either power up in CommandMode or Data Mode. Normally, when first received from the factory, theunit will power up in Command Mode. In this mode of operation, themodule “autobauds,” meaning that it will adapt to the baud rate of the DTEequipment to which it is connected. Therefore, when in Command Mode,you may change the baud rate of your equipment, and the CompactRF willautomatically adjust to this baud rate once an AT string is issued. The newbaud rate is stored in register S102. Several baud rates ranging from 2400to 19200 may be selected.You can place the modem into Data Mode either by:• Issuing the answer command (ATA <ENTER>); or,• Issuing the online command (ATO <ENTER>).
CompactRFTM Operating Manual: Chapter 3 Modes of Operation 15The escape sequence will notbe accepted unless both theCompactRFTM and theterminal are set to the samebaud rateDATAMODESLEEPMODECOMMANDMODEESC \SLEEP\SLEEP\SLEEP\SLEEP\SLEEPESC \SLEEP\SLEEP \CONFIG\SLEEP \CONFIGFigure 5a - MenuInterface State DiagramDATAMODESLEEPMODECOMMANDMODE\SLEEP\SLEEP\SLEEP\SLEEP\SLEEP(ATA or ATO Command) DTR or Escape Sequence\SLEEPFigure 5b - AT InterfaceState DiagramThe modem will now attempt to communicate with other CompactRFmodules. While in Data Mode, the modem will communicate through theserial port at the same baud rate as was last used in Command Mode2.To return to Command Mode, you can either:• Send the escape sequence. (The escape sequence consists of 1 secondof inactivity, followed by the characters ‘+++’ followed by anothersecond 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 hasbeen set to. If the modem is set to 19200 baud, and the escape sequence isissued at 9600 baud, for example, the modem will not recognize it, and willnot go into Command Mode.3.3.2 Switching Between Menu Interface and Data ModeWhen configured for Menu Interface operation, the CompactRF may beplaced 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.To switch back to Data Mode, from the main menu, hit the ESC key. Youshould see the response “Running...” The modem will run in Data Mode atthe baud rate setting defined by Menu Item 2) Serial Baud Rate.3.4 Sleep ModeAs mentioned at the beginning of this chapter, the CompactRF has a sleepmode of operation. Figure 5 is a state diagram representation of the threemodes of operation. Figure 5a is the menu interface state diagram, andFigure 5b is the AT interface state diagram. The CompactRF enters intoSleep Mode when \SLEEP is asserted (active low). The module remains inSleep Mode until this line is deasserted. See Chapter 2 for timinginformation. When in Sleep Mode, the module drives all outputs pins (Pins6-11,23-25,27) at their inactive levels. 2 It is possible to enter into Data Mode at a different baud rate from what iscurrently being used in Command Mode by issuing the commandATS102=x, where x is one of the valid baud rates. Care must be takenwhen setting the baud rate in this manner. If you issue another AT stringafter attempting to set the baud rate using ATS102 <ENTER>, the modemwill again autobaud and automatically revert to the baud rate of the hostequipment. For example, if your equipment is running at 9600 baud andyou wish to set up the modem to run at 19200 baud, the following commandline entry would achieve this:ATS102=2&WA <ENTER>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 themodem into Data Mode. Once in Data Mode, the modem is unable toautobaud, and is fixed at 19200 baud. By combining several commands intoone command line entry, and then immediately putting the modem online,the modem is not given a chance to autobaud back to 9600.
16 CompactRFTM Operating Manual: Chapter 3 Modes of Operation
CompactRFTM Operating Manual: Chapter 4 Configuration 174. ConfigurationMSNetwork 1MSRMSRNetwork 2Figure 6. Basic NetworksThis chapter provides a detailed description of the various operatingparameters of the CompactRF. Section 4.1 provides a quick-start approachwhich outlines the minimum requirements for establishing communicationbetween two CompactRF modules. The settings will not necessarily provideoptimal performance for your application, but will verify that the modules arefunctioning correctly.Section 4.2 describes the AT Command interface. Section 4.3 describes theset of registers which are unique to AT operation, and not used in menumode.Section 4.4 covers all parameters that are common to both the AT Commandinterface and the Menu interface.4.1 Quick Start ApproachWhether you are using the AT Command interface or the Menu interface,there are several parameters that must be set in order to establishcommunication 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 globalcommand may be used to quickly configure the modem for a particular typeof operation. For example, to quickly implement Network 1, Factory default1 would be applied to the Master, and Factory default 2 would be applied tothe 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 getyou started and only ensure that a link can be established, but do notnecessarily provide the best performance. Optimization of thecommunications link is discussed in later sections.To implement the basic network illustrated in Figure 6, Network 1,Using AT Commands Using Menu InterfaceConnect a straight-through serial cable between the development board and theterminalConnect an antenna to the modulePower up the development boardSee Section 3.3 If you have problemsgetting into Command Mode.Configure the unit to Factory Setting 1by typing AT&F1 <return>. This putsthe unit into Master Point-to-pointmode.Store these settings to memory by typingAT&W <return>.Configure the unit to Factory Setting 1 byselecting menu option F). You shouldsee the following:Factory Settings 1) Factory Master 2) Factory Slave 3) Factory Slave Through Repeater 4) Factory Repeater* 5) ManualSelect menu item 1)Put the modem into Data Mode bytyping ATA (or ATO) <return> Put the modem into Data Mode bypressing the ESC key.Perform above steps for the second unit, using Factory Setting 2 instead of FactorySetting 1. This will configure the second unit as a Slave.
18 CompactRFTM Operating Manual: Chapter4 ConfigurationThe units should now be communicating. Remember, the parameters definedby Factory Settings 1 and 2 will likely not be the most ideal for yourapplication, but will quickly allow you to test the units. A complete summaryof the settings defined by all four factory settings can be found in AppendixC. Factory Default Settings.Settings are not immediately stored in non-volatile memory when using ATCommands, therefore, the command &W is issued to store the currentconfiguration into non-volatile memory. Settings are retained even afterpowering down. All user selectable parameters for the CompactRFTM aredescribed in detail in Section 4.4: Configuration Settings.Checking the LinkTo check if the units are communicating, observe the LED indicators on thedevelopment board. If the link is good, up to three RSSI LED’s on theMaster and Slave modems should be active; and if the link is absent (due to afault at one end or another, such as misconfiguration), the LED’s will be ineither “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 arereceived at the Master modem. As data is sent from Slave to Master, the RXindicator should blink on as correct packets of data are received. It isrecommended that if the CompactRFTM will be deployed in the field wherelarge distances separate the units, the modems should be configured andtested in close proximity (e.g., in the same room) first to ensure a good linkcan be established and settings are correct. This will facilitatetroubleshooting, should problems arise.4.2 AT CommandsSeveral AT Commands are supported by the CompactRFTM. The commandsdiscussed in this section do not have a menu interface equivalent. Morecommands 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 asdesired. The command line holds up to 16 characters, not including the ATprefix. If you want to send more than one command line, wait for aresponse before entering the AT prefix at the start of the next command line.To re-execute the previous command, enter A/. The modem will executethe previous command line.When in Command Mode, the modem “autobauds”, meaning that it willautomatically adjust to the baud rate of the terminal. You may change theterminal baud rate while in Command Mode without losing communicationwith the modem.For the AT command protocol, an escape sequence consists of threeconsecutive escape codes preceded and followed by at least 1 second ofinactivity. Typically, the ‘+’ character is used as the escape code.+++ preceded and followed by 1 second of inactivity
CompactRFTM Operating Manual: Chapter 4 Configuration 19Note that the terminal must be configured to the same baud rate as themodem in order for the modem to recognize the escape sequence. Themodem is unable to “autobaud” while in Data Mode.The following is a description of all available commands. ‘*’ denotesstandard factory settings. All of the following commands must be precededby “AT”.AAnswerThe A command causes the modem to attempt to connect with anotherremote modem (Type ATA <return>).ECommand EchoYour modem is preset to return (or echo) commands to the hostmicroprocessor when in Command Mode.E0 No Command Echo*E1 Command EchoIIdentificationThe I command returns various modem information settings.I0 Product Code (CompactRF)I2 Issue ROM Check (OK or ERROR)I3 Product Identification (Firmware Version)I4 Firmware DateI5 Firmware CopyrightI6 Firmware TimeOOn-line ModeThe O command attempts to put the modem online and communicate with aremote modem.QQuiet ModeYour modem is preset to send responses when it executes commands, andthere after to keep the host informed of its status.*Q0 Enable modem responsesQ1 Disable modem responsesVResult Codes displayYour modem can either display result codes as words or numbers.V0 Display Result Codes as numbers*V1 Display Result Codes as wordsWConnection ResultThis parameter determines the modem response at the transition from DataMode to Command Mode*W0 Reports computer (DTE) baud rate as CONNECT xxxxW1 Reports wireless rate between modems as CARRIER xxxx.W2 Reports modem (DCE) baud rate as CONNECT xxxxZReset and load stored configurationThe Z command resets the modem and loads the stored configuration.
20 CompactRFTM Operating Manual: Chapter4 Configuration&V View ConfigurationThe &V command displays all S registers and their current values.&E Framing Error Check NOT YET IMPLEMENTEDThis 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 thrownout. When enabled, the modem also does a parity check. Note that the dataformat (number of data bits, parity type, and number of stop bits) is definedby S register 110.*&E0 Disable Framing Error Check&E1 Enable Framing Error Check&W Write Configuration to MemoryThe &W command stores the active configuration into the modem’s non-volatile memory.Sxxx? Read S register valueThis command causes the modem to display the current setting of S registerxxx.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 CodesThe CompactRFTM module can either display the results of a command aseither text strings or numerical data. The following chart shows resultingtext string and corresponding numeric result.0OK3NO CARRIER4ERROR7CONNECT 24008CONNECT 36009CONNECT 480010 CONNECT 720012 CONNECT 960013 CONNECT 1440014 CONNECT 1920015 CONNECT 2880017 CONNECT 3840018 CONNECT 5760033 CONNECT 11520062 CARRIER 4500064 CARRIER 20000
CompactRFTM Operating Manual: Chapter 4 Configuration 21S Registers 2 through 5cannot be stored to non-volatile memory.4.3 AT RegistersThe parameters described in this section apply to AT Command operationonly.S Register 0 - Auto AnswerIf this register is set to zero, the modem will power up in command mode. Ifthis register is non-zero, the modem will power up in data mode.S Register 2 - Escape CodeThis 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 fromreturning to the Command Mode. This register cannot be stored to non-volatile memory. If the modem is reset, or powered down, the default valueis restored.Default is ‘+’ (decimal 43).S Register 3 - CR Control CodeThis 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 thecharacter that appears after the modem sends a response. This registercannot be stored to non-volatile memory. If the modem is reset, or powereddown, the default value is restored.Default is ‘CR’ (decimal 13).S Register 4 - Linefeed Control CodeRegister S4 sets the ASCII value of the linefeed character.The modem sends the linefeed character after sending a carriage returncharacter when sending text responses. This register cannot be stored tonon-volatile memory. If the modem is reset, or powered down, the defaultvalue is restored.Default is ‘LF’ (decimal 10).S Register 5 - Backspace Control CodeRegister S5 sets the ASCII value of the backspace character.This character is both the character created by entering BACKSPACE andthe character echoed to move the cursor to the left. This register cannot bestored to non-volatile memory. If the modem is reset, or powered down, thedefault value is restored.Default is ‘BS’ (decimal 8).
22 CompactRFTM Operating Manual: Chapter4 Configuration&F1 &F2Master Slave&F1 &F4&F3Master Repeater Slave4.4 Configuration SettingsThe parameters described in this section affect the operating characteristicsof the CompactRF module. All the settings described in this section can beconfigured using either the AT Command interface or the menu interface.AT MenuDCD (Data Carrier Detect) &C MThe &C command controls the modem’s DCD output signal to the hostmicroprocessor. This command determines when the DCD is active.&C0 DCD is always ON*&C1 DCD on when modems are synchronized. DCD is alwayson when unit is configured as Master.&C2 DCD used for output data framing and Modbus mode.See page 24 for details.AT MenuDTR (Data Terminal Ready) &D NThe &D command controls what action the modem performs when the DTRinput line is toggled. The DTR input is controlled by the hostmicroprocessor.*&D0 DTR line is ignored&D1 Not Supported&D2 DTR disconnects and switches to Command Mode&D3 DTR disconnects and resets modem. Modem will remainin this state until DTR again goes active.AT MenuLoad Factory Default Configuration &F FThe &F command resets the modem and loads the default factoryconfiguration.&F1 Master Point-to-Multipoint. Designed to communicatewith modems configured as &F2 or &F3.&F2 Slave. Designed to communicate with another modemconfigured as &F1.&F3 Repeater. Designed to communicate with modemsconfigured as &F1 and &F4.&F4 Slave working with factory default Repeater and factorydefault Master. Communicates directly with Repeaterconfigured as &F3.
CompactRFTM Operating Manual: Chapter 4 Configuration 23Only one Master can existfor each network.AT MenuHandshaking &K AThis command controls the handshaking between the modem and hostmicroprocessor.&K0 Disable handshaking&K2 RTS/CTS input data framing. See page 33 for details.*&K3 Enable hardware handshaking (RTS/CTS)AT MenuDSR (Data Set Ready) &S OThis command controls the DSR line for the modem, and determines whenit is active&S0 DSR is always ON*&S1 DSR is ON in Data Mode, OFF in Command ModeAT MenuOperating Mode S101 1The Operating Mode (register S101) partly defines the “personality” of theCompactRFTM module. Allowable settings for this register are 1 through 4as follows:.• S101=1 Master Point to Multipoint• S101=2 Master Point to Point• S101=3 Slave• S101=4 RepeaterThe default for this register depends on which factory default is selected asshown 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, thereis always only one Master. All other units should be configured as eitherSlaves or Repeaters. When defined as a Point-to-Multipoint Master, themodem broadcasts data to all Slaves and Repeaters in the network, and isalso the ultimate destination for data transmitted by all Slaves andRepeaters. In addition, the Master defines the following network parametersto be utilized by all other modems in the network (See the appropriatesections for a complete description of these parameters):nMaximum Packet Size (S112)nMinimum Packet Size (S111)nLink Handshaking (S122)nWireless Link Rate (S103)nHop Interval (S109)
24 CompactRFTM Operating Manual: Chapter4 ConfigurationPHP=1 PHP=2PHP=1SHP=2MasterRepeaterSlaveNetwork 50Hop Pattern 1Hop Pattern 2Figure 7 - RepeaterOperationMaster RepeaterSlaveRepeaterSlavePHP=1 PHP=1SHP=2PHP=2PHP=2SHP=3 PHP=3Hop-Pattern 1Hop Pattern 2Hop Pattern 3Figure 8 - A NetworkUtilizing Three HoppingPatternsIf there is no DTE connectedto the Repeater, turn offhandshaking (&K0) and setthe baud rate to 115K.2)Master - Point to Point. This mode of operation is identicalto Master Point-to-Multipoint, with the exception that the Master onlybroadcasts to one particular Slave or Repeater. The modem with whichcommunication occurs is defined by the Unit Address (S105). For example,if a Slave has been assigned Unit Address 100, and the Master wishes tocommunicate with that Slave, the Master must also be assigned a UnitAddress of 100. If there are Repeaters in the network, they will pass thepacket through to the Slave, and vice versa. Because Repeaters also haveSlave functionality (i.e., a Repeater can be connected to a terminal), theMaster can choose to communicate solely with a Repeater. This would beaccomplished by assigning the same Unit Address to both the Master andthe Repeater.3)Slave. Up to 65534 Slaves may exist in a network, all of whichcommunicate with the common Master (either directly or via Repeater(s)).Slaves cannot directly communicate with other Slaves, nor can theyacknowledge packets of data sent by the Master. Clearly this would causeconflicts when there are multiple Slaves. The Master does, however, sendacknowledgements to all messages it receives from Slaves. The Masterinitiates communications by sending a broadcast message to all Slaves. AllSlaves are free to respond in a “Slotted ALOHA” fashion, meaning that eachSlave can choose one of several windows in which to transmit. If therehappens to be two Slaves attempting to talk at the same time, the Mastermay not receive the data, and the Slaves therefore would not get anacknowledgement. At this point, the Slaves would attempt to get theinformation through at random time intervals, thus attempting to avoid anymore conflicts. Special parameters which control the Slave’s responsecharacteristics can be modified with S Registers S115 and S213.4) Repeater. A more precise title would be Repeater/Slave, because aRepeater also has much of the same functionality as a Slave. A terminal canbe connected at the Repeater location and communicate with the Masterterminal. There is no restriction to the number of Repeaters in a network,allowing for communication over virtually limitless distances. The presenceof one Repeater in a network automatically degrades system throughput byhalf. Additional Repeaters, regardless of the quantity, do not diminishsystem throughput any further. To understand Repeater operation, considerthe module as belonging to two hopping patterns at the same time: ThePrimary Hopping Pattern and the Secondary Hopping Pattern. In Figure 7,the Master belongs to Hopping Pattern 1, and communicates with theRepeater on this hopping pattern. The Slave belongs to Hopping Pattern 2,and communicates with the Repeater on this hopping pattern. The wholesystem belongs to Network 50 (i.e., all units must be assigned the sameNetwork Address (S104), which in this case was selected to be 50. Notethat Slaves and Master only communicate on their respective PrimaryHopping Pattern. Repeaters communicate on the Primary Hopping Patternwhen communicating with the Master (or with another Repeater betweenitself and the Master). Repeaters communicate on their Secondary HoppingPattern when communicating with Slaves (or with another Repeater betweenitself and the Slaves). Figure 8 shows another example.If the Repeater is not also being used as a Slave (there is no DTE connectedto the serial port), it is recommended that the Repeater’s baud rate be set to115K, and that handshaking be disabled (&K0). This will help ensure asmooth flow of data through the network.
CompactRFTM Operating Manual: Chapter 4 Configuration 25The Master determines theWireless Link Rate. Thissetting on all other modemsis ignored..AT MenuSerial Baud Rate S101 1The Serial Baud Rate is the current speed that the modem is using tocommunicate with the DTE. When the AT command prefix is issued, themodem performs an ‘autobaud’ operation and determines what the currentDTE baud rate is set to. The S register value returns the current setting ofthe DTE baud rate.The possible values are:* 1 1152002 576003 384004 288005 192006 144007 96008 72009 480010 360011 2400It is generally advisable to choose the highest rate that your terminalequipment will handle to maximize performance, unless a limitation on theavailable bandwidth is desired. If the DTE is a personal computer, the portcan usually be used reliably at 115200.
26 CompactRFTM Operating Manual: Chapter4 ConfigurationSelect a Network Addressand assign it to all unitswhich will be included in thenetwork.Use the same Unit Addresson both units for point-to-point mode. In multipointmode, set each Slave andRepeater to a different UnitAddress.Valid Unit Addresses are 1to 65535.AT MenuNetwork Address S104 3The Network Address defines the communications network to whichindividual units can be a part of. By establishing a network under acommon Network Address, the network can be isolated from any otherconcurrently operating network. As well, the Network Address provides ameasure of privacy and security. Only those units which are members of thenetwork will participate in the communications interchange. Valid valuesfor the Network Address range from 0 to 65535, inclusive.To enhance privacy and reliability of communications where multiplenetworks may operate concurrently in close proximity, it is suggested that anatypical value be chosen – perhaps something meaningful yet not easilyselected by chance or coincidence.Default is 1.AT MenuUnit Address S105 4In 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 UnitAddress uniquely identifies each Slave and Repeater from one another.Each unit in a multipoint system must have a unique Unit Address rangingfrom 1 to 65535. Do not use 0 as a Unit Address, and do not use a UnitAddress more than once within the same Network. This is required becausethe Master must be able to acknowledge each unit individually, based on theUnit Address.AT MenuPrimary Hopping Pattern S106 5Secondary Hopping Pattern S206 BSince the CompactRFTM is a frequency-hopping modem, the carrierfrequency changes periodically according to one of 30 pseudo-randompatterns, defined by the Primary and Secondary Hopping Patterns. Validentries for each are 0 through 29.The concept of Primary and Secondary Hopping Patterns was introduced inthe 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;
CompactRFTM Operating Manual: Chapter 4 Configuration 27Master SlaveMaster Repeater SlaveMaster Repeater1 Repeater2 SlaveSlaves and Masters do notuse Secondary HoppingPatternsRemember to assign aunique Unit Address (1 to65535) to each unit in thesystemthe following diagrams illustrate the methodology for deploying simple tocomplicated networks: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]It is reasonable to consider a Repeater as being both a Slave and a Master,alternating between Primary and Secondary Hopping Patterns as the unitchanges channel. Consider R1 in the illustration below. Whencommunicating with the Master, R1 is acting like a Slave on PrimaryHopping Pattern 1. When communicating with R2 and S4, R1 is acting likea Master on Secondary Hopping Pattern 2. If multiple Repeaters are used,they should have different Secondary Hopping Patterns:←→ R1[1,2] ←→ R2[2,5] ←→ S3[5]M[1] ←→ S4[2]←→ R5[1,3] ←→ R6[3,6] ←→ S7[6]←→ R8[1,4] ←→ S9[4]Note that all units have a unique Unit Address.Networks of any complexity can be created by linking multiple Repeatersand Slaves:←→ R1[1,2] ←→ S2[2]←→ S3[2]←→ ←→ R5[3,6] ←→ S6[6]M[1] R4[1,3] ←→ S7[6]←→ R8[3,7] ←→ R9[7,8] ←→ S10[8]←→ S11[1]←→ S12[1]With a limitation of 62 hopping patterns, one might suspect that there is alimitation to the number of repeaters in a system. However, if the units arefar enough away from one another, hopping patterns may be reused indifferent sections of the network, without causing interference.
28 CompactRFTM Operating Manual: Chapter4 ConfigurationAll units within a networkmust use the sameencryption key.AT MenuEncryption Key S107 6The Encryption Key provides a measure of security and privacy ofcommunications by rendering the transmitted data useless without thecorrect 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 forcommunications to succeed.AT MenuOutput Power Level S108 7The Output Power Level determines at what power the CompactRFTMtransmits. The CompactRFTM can operate with very low power levels, so itis recommended that the lowest power necessary is used; using excessivepower contributes to unnecessary “RF pollution”.The allowable settings are:01 mW110 mW*2 100 mW31000 mWIdeally, you should test the communications performance between unitsstarting from a low power level and working upward until the RSSI issufficiently high and a reliable link is established. Although the conditionswill vary widely between applications, typical uses for each setting aredescribed below:Power Use1 mW For in-building use, typically provides a link up to 300 feet on thesame floor or up/down a level. Outdoors, distances of 1 km can beachieved if high-gain (directional) antennas are placed high aboveground 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(1 W)Typically provides communications up to a distance of 1000 feet ormore in-building on the same floor or up/down a few levels,depending on building construction (wood, concrete, steel, etc.). Inideal 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 warningbelow.
CompactRFTM Operating Manual: Chapter 4 Configuration 29FCC RegulationsThe hopping interval iscontrolled by the master.The slave and repeater unitswill use the hopping intervalsetting from the master.IMPORTANT:FCC Regulations allow up to 36 dBi effective radiated power (ERP).Therefore, the sum of the transmitted power (in dBm), the cabling lossand the antenna gain cannot exceed 36 dBi.1 mW = 0 dBm10 mW = 10 dBm100 mW = 20 dBm1000 mW = 30 dBmFor example, when transmitting 1 Watt (30 dBm), the antenna gaincannot exceed 36 - 30 = 6 dBi. If an antenna with a gain higher than 6dBi were to be used, the power setting must be adjusted appropriately.Microhard Systems Inc. limits the CompactRF’s transmitted power to100mW for all units purchased with antennas with gain above 6dBi.AT MenuHopping Interval S109 9This option determines the frequency at which the modems change channel.Note that the Master controls this parameter for the entire network. Thissetting is ignored in units configured as Slaves or Repeaters.The allowable settings are 20 to 255. There is a multiplying factor of0.74ms. For example, if you set the Hopping Interval to 20, the actualhopping interval will be 20 x 0.74ms = 14.8ms.See Appendix D for optimal Hopping Interval settings in relation to packetsize and link rate.AT MenuData Format S110 CThis register determines the format of the data on the serial port. Allowablesettings are:*1 8 bits, No Parity, 1 Stop28 bits, No Parity, 2 Stop38 bits, Even Parity, 1 Stop48 bits, Odd Parity, 1 Stop57 bits, No Parity, 1 Stop67 bits, No Parity, 2 Stop77 bits, Even Parity, 1 Stop87 bits, Odd Parity, 1 Stop97 bits, Even Parity, 2 Stop10 7 bits, Odd Parity, 2 Stop11 9 bits, No Parity, 1 Stop
30 CompactRFTM Operating Manual: Chapter4 ConfigurationThe Minimum andMaximum Packet Size iscontrolled by the Master.The Slave and Repeater unitswill use the Minimum andMaximum Packet Sizesetting from the Master.AT MenuPacket Minimum Size S111 GPacket Maximum Size S112 HPacket Character Timeout S116 IThese settings determine the conditions under which the modem willtransmit accumulated data over the air.S Register 111 - Minimum SizeValid entries for this register are 1 to 255 bytes, which defines the minimumnumber of bytes to receive from the DTE before encapsulating them in apacket and transmitting over the air.Note that the minimum packet size for all modems in the network isdetermined by the Master only. This setting is ignored in all Slave andRepeater modems. The default is 1 byte.S Register 112 - Maximum SizeThis setting has a range of 2 to 255, and defines the maximum number ofbytes from the DTE which should be encapsulated in a packet. This valueshould be greater than the minimum packet size, but not smaller than isnecessary for reliable communications. If the wireless link is consistentlygood 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) anddata is frequently retransmitted, the maximum packet size should bereduced. This decreases the probability of errors within packets, andreduces the amount of traffic in the event that retransmissions are required.Note that the maximum packet size for all modems in the network isdetermined by the Master only. This setting is ignored in all Slave andRepeater modems. The default is 255 bytes.S Register 116 - Packet Character TimeoutThis register has valid entries of 0 to 254 milliseconds. The PacketCharacter Timeout timer looks for gaps in the data being received from theDTE. The timer is only activated after the Minimum Packet Size has beenaccumulated in the modem. After which, if the timer detects a gap in thedata exceeding the Packet Character Timeout value, the modem willtransmit the data.The CompactRFTM will accumulate data in its buffers from the DTE untilone 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 PacketCharacter Timeout interval has elapsed.The default for the Packet Character Timeout is 9 ms. If set to 0 ms, theunit will buffer exactly the minimum packet size before transmitting.
CompactRFTM Operating Manual: Chapter 4 Configuration 31AT MenuPacket Retransmissions S113 JThis register applies to both Master and Repeater operation. It does notapply to Slave operation. The Master will retransmit each data packetexactly the number of times defined by the Packet Retransmissionsparameter. The Master retransmits once at the beginning of each hoppinginterval until the limit is reached. This parameter is not necessary in Slaveunits since all Slaves receive acknowledgement from the Master. Asdiscussed previously, the Repeater effectively behaves as both a Master anda 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 Repeatersexactly the number of times defined by the Packet Retransmissionsparameter.Recipients of the packet will discard any duplicates The valid settings forthis parameter are 0 to 255 retransmissions. The default is 2.AT MenuPacket Retry Limit S213 KPacket Retry Limit is analogous to Packet Retransmissions, but specificallyapplies to Slaves and Repeaters. This parameter is not used by the Master.Because the Slave has the advantage of receiving acknowledgements fromthe Master, it is not necessary to blindly retransmit each packet. If the Slavedoes not get an acknowledgement on the next hop, it will retransmit itspacket. This will continue until the Packet Retry Limit is reached or anacknowledgement is received. If the limit is reached, the modem will giveup and discard the data. Valid settings are 0 to 255 retries. The defaultvalue is 2.The Repeater makes use of this parameter when it is tuned to its PrimaryHopping Pattern and is acting like a Slave.
32 CompactRFTM Operating Manual: Chapter4 ConfigurationAT MenuPacket Repeat Interval S115 LA parameter that is specific to Slaves and Repeaters is the Packet RepeatInterval.The allowable settings are 1 through 255. The default is 1.This parameter defines a range of random numbers that the Slave will use asthe next slot in which it will attempt to send the packet. For example, if thisregister is set to 7, the Slave will choose a number between one and seven asthe next slot in which to transmit. Suppose the random number generatorpicks 5, then the Slave will transmit in the fifth time slot. A Slave willtransmit a maximum of once per hopping interval, however, depending onthe duration of the hopping interval and the maximum packet size, morethan one slot per hop is potentially available. The Slave will transmit morefrequently when a Repeat Interval with a smaller range is selected. Choose1 to have the Slave transmit in the first available slot. Choose higherintervals for less frequent transmission, or to avoid collisions between manySlaves in the system.AT MenuLink Handshaking S122 PLink Handshaking is controlled only by the Master unit. If the Master runsout of free buffers, it will command all Slaves and Repeaters to hold theirdata. Once the Master is ready to receive data it will allow the Slaves andRepeaters to transmit. Possible values are ‘1’ - Enabled and ‘0’ - Disabled.The default is 1. This register is ignored by all Slave and Repeater units.AT MenuModbus Mode S117 QModbus Mode allows for the CompactRFTM to be fully Modbus compatible.Please contact Microhard Systems for assistance when configuring the unitfor Modbus operation. Optimal Modbus settings rely on several other SRegister parameters.The allowable settings for this register are:*0 Disabled1Enabled
CompactRFTM Operating Manual: Chapter 4 Configuration 33AT MenuRTS/DCD Framing 120 RDCD Timeout 121 SThe CompactRFTM supports two special types of data framing:• Input (or RTS/CTS) Data Framing; and,• Output (or DCD) Data FramingInput Data Framing is enabled by configuring the Handshaking Parameter as&K2. This type of framing makes use of the S120 parameter as illustratedin Figure 9. Parameter S120 can be set to any value between 0 and 254 ms.RTSCTSTXDS120 (ms)Data going into MHX-9100 to 1 msFigure 9 - Input Data FramingTo enable output (DCD) data framing, set the Data Carrier Detect parameteras &C2. This type of framing uses both S120 and S121 registers as shownin Figure 10. Valid ranges for each parameter are 0 to 254 ms.DCDRXD Data leaving MHX-910S120 (ms) S121 (ms)Figure 10 - Output Data FramingAT MenuRSSI Reading S123 TThis register displays the average signal strength in dBm over the previousfour hop intervals. Valid RSSI readings apply only to units configured asSlave or Repeater.
34 CompactRFTM Operating Manual: Chapter4 Configuration
CompactRFTM Operating Manual: Chapter 5 Installation 355. InstallationThe installation, removalor maintenance of allantenna components mustbe carried out byqualified and experiencedprofessionals.The installation, removal or maintenance of all antennacomponents must be carried out by qualified andexperienced professionals.The CompactRF complies with FCC part 15 at the modular level foroperation in the license-free 902-928 MHz ISM band. This chapterprovides guidelines for installing and deploying equipment whichincorporates the CompactRF module.5.1 Estimating the Gain MarginSuccessful communication between CompactRF modules is dependent onthree main factors:• System Gain• Path Loss• InterferenceSystem gain is a calculation in dB describing the performance to beexpected between a transmitter-receiver pair. The number can be calculatedbased on knowledge of the equipment being deployed. The following fourfactors 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 betweenthe transmitting antenna and the CompactRF module)3. Receiver gain (Receiving antenna gain minus cabling loss between thereceiving antenna and the module)4. Receiver sensitivity (Specified as -103 dBm on the CompactRFmodule)In the following illustration, the transmitting antenna has a gain of 6 dB, andthe receiving antenna has a gain of 3 dB. The cable loss between themodule and the antenna is 2 dB on both the transmitting and receiving side.Transmitter30 dBmOutput PowerReceiverSensitivity =-103 dBmCable Loss = 2 dBCable Loss = 2 dBAntenna Gain = 6 dB Antenna Gain = 3 dBThe power level has been set to 30 dBm (1W) on the transmitter, and thereceiver sensitivity for the CompactRF is -103 dBm.System gain would be calculated to be:30 - 2 + 6 + 3 - 2 + 103 = 138 dB.
36 CompactRFTM Operating Manual: Chapter 5 InstallationBase Height (m)MobileHeight(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) betweenequipment 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 ensurereliable communication. Gain margin is the difference between system gainand path loss. Referring to the same example, if the path loss is 100 dB, thegain margin would be 38 dB, which is more than adequate for reliablecommunication.Path loss is a very complicated calculation which mainly depends on theterrain profile, and the height of the antennas off the ground.The following table provides path loss numbers for varying antenna heightsand antenna separation: These numbers are real averages taken from ruralenvironments. They do not apply to urban, non-line-of-sight environments.Distance(km)Base Height(m)Mobile Height(m)Path Loss(dB)5 15 2.5 116.55 30 2.5 110.98 15 2.5 124.18 15 5 117.78 15 10 10516 15 2.5 135.316 15 5 128.916 15 10 116.216 30 10 109.616 30 5 122.416 30 2.5 128.8Once the equipment is deployed, you can verify the signal strength byentering into Command Mode and reading Register S123. This registerprovides the average signal strength in dBm. The minimum strength forcommunication is roughly -103 dBm. For consistent reliablecommunication, you should try to deploy the equipment such that signalstrength exceeds -95 dBm.
CompactRFTM Operating Manual: Chapter 5 Installation 375.2 Antennas and CablingThis section describes the recommended procedure for installing cablingand antennas for use with the CompactRF module.5.2.1 Internal CablingThe most common method for installing the module is to run a cable fromthe module’s SMA connector to an N-male bulkhead connector on thechassis of the equipment as shown in Figure 11LMR195 Cable with SMA maleconnectorand N-malebulkheadconnector N-male connectorSMA male connectorFigure 11. Suggested Internal CablingWith losses of 10.7 dB/100ft, LMR195 is a high quality cable ideal for usewith the CompactRF’s SMA connector. Losses are negligible for the shortpiece used within the chassis. Additional losses up to 0.5 dB may be presentin the SMA and N connections.
38 CompactRFTM Operating Manual: Chapter 5 InstallationThe installation, removal ormaintenance of all antennacomponents must be carried outby qualified and experiencedprofessionals.Never work on an antenna systemwhen there is lightning in thearea.Direct human contact with theantenna is potentially unhealthywhen the CompactRF isgenerating RF energy. Alwaysensure that the CompactRFequipment is powered downduring installation.s5.2.2 Installing External Cables, Antennas and LightningArrestorsThe installation, removal or maintenance of all antenna components must becarried 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 theCompactRF is generating RF energy. Always ensure that the CompactRFequipment is powered down during installation.Surge ArrestorsThe most effective protection against lightning is to install two lightning(surge) arrestors. One at the antenna, and the other at the interface with theequipment. The surge arrestor grounding system should be fullyinterconnected with the transmission tower and power grounding systems toform a single, fully integrated ground circuit. Typically, both ports on surgearrestors are N-female.CablingThe following coax cables are recommended:Cable Loss (dB/100ft)LMR 195 10.7LMR 400 3.9LMR 600 2.5Factors to take into consideration when choosing a cable are:• price;• bend radius limitations (the lower performance cables generally canbend more sharply)• performance requirements; and,• distance between the equipment and the antenna.When installing the cable, always begin fastening at the top near the antennaconnector/surge arrestor. The cable must be supported at the top with ahose 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. Ifproperly grounded surge arrestors are not installed at both the top and thebottom of the cable, then the cable should be grounded to the tower at theselocations using a cable grounding kit. If the tower is non-conductive, then aseparate conductor, physically separate from the cable, should be run downthe tower.
CompactRFTM Operating Manual: Chapter 5 Installation 39To comply with FCC regulations,.you must limit ERP to 36 dBm orless.AntennaBefore choosing an antenna, you should have some knowledge of the pathloss and the topology of the equipment. If the equipment is in a fixedlocation and is to communicate with only one other unit also in a fixedlocation, then a Yagi antenna is suitable. Choose a Yagi with enough gainto ensure adequate gain margin. When deploying the Yagi, point theantenna towards the intended target, ensuring the antenna elements areperpendicular 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 fromthe antenna cannot exceed +36 dBm ERP.With the CompactRF set to full power, ERP is calculated as follows: ERP = 30 - (Cabling and Connector Losses) + (Antenna Gain) < 36Use the guidelines in the previous section for calculating cable andconnector losses. If cabling and connector losses are 2 dB, then themaximum allowable gain of the antenna will be 8 dB.External FilterAlthough the CompactRF is capable of filtering out RF noise in mostenvironments, there are occasions that require external filtering. Pagingtowers, and cellular base stations in close proximity to the CompactRFantenna can desensitize the receiver. Microhard Systems’ external cavityfilter eliminates this problem. The filter has two N-female ports and shouldbe connected in line at the interface to the RF equipment.WeatherproofingType N connectors are not weatherproof. All connectors should be tapedwith rubber splicing tape (weatherproofing tape), and then coated with asealant.
40 CompactRFTM Operating Manual: Chapter 5 Installation
CompactRFTM Operating Manual: Appendix A Modem Command Summary 41A. Modem Command SummaryThe following provides a command summary for the CompactRFTM. Factory settings are denoted with a ‘*’.AT CommandsAAnswerECommand EchoE0 No Echo* E1 Command EchoIIdentificationI0 Product CodeI2 ROM Checksum testI3 Firmware VersionI4 Firmware DateI5 CopyrightI6 Firmware TimeOOn-line ModeQQuiet Mode* Q0 Enables Result CodesQ1 Disables Result CodesVResult Codes DisplayV0 Display as Numbers* V1 Display as WordsWConnection Result* W0 Reports DTE as CONNECT xxxxW1 Reports computer (DTE) rate and wireless ratebetween modems as CARRIER xxxx.W2 Reports DCE as CONNECT xxxxZReset 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 memorySxx? Read S register valueSxx=yy Set S register valueResult Codes0OK 12 CONNECT 96003NO CARRIER 13 CONNECT 144004ERROR 14 CONNECT 192007CONNECT 2400 15 CONNECT 288008CONNECT 3600 17 CONNECT 384009CONNECT 4800 18 CONNECT 5760010 CONNECT 7200 33 CONNECT 11520064 CARRIER 20000 62 CARRIER 45000S RegistersS0 Auto Answer [0...255]0 = power up in Command Mode,non-zero = power up in Data ModeS2 Escape code [0...255] default ‘+’S3 CR character [0...255] default <cr>S4 Line Feed [0...255] default <lf>S5 Backspace [0...255] default <bs>S101 Operating Mode1 - Master Point to Multipoint2 - Master Point to Point3 - Slave4 - RepeaterS102 Serial Baud Rate*1 = 115200, 2 = 57600, 3 = 384004 = 28800, 5 = 19200, 6 = 144007 = 9600, 8 = 7200, 9 = 4800,10 = 3600, 11 = 2400S103 Wireless Link Rate2 = Fast w/o FEC*4 = Fast with FECS104 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 Level0 = 1 mW, 1 = 10 mW, *2 = 100 mW3 = 1000 mWS109 Hopping Interval1 = 8 msec, 2 = 12 msec, 3 = 16 msec,4 = 20 msec, 5 = 30 msec, 6 = 45 msec,7 = 80 msec, *8 = 120 msecS110 Data Format* 1 = 8N1, 2 = 8N2, 3 = 8E1, 4 = 8O15 = 7N1, 6 = 7N2, 7 = 7E1, 8 = 7O19 = 7E2, 10 = 7O2, 11 = 9N1S111 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 = 1S116 Packet Character Timeout [0...254 ms]S117 Modbus Mode*0 = Disabled, 1 = EnabledS120 RTS/DCD Framing Interval [0...254 ms]S121 DCD Timeout [0...254 ms]S122 Link Handshaking [0=Disabled, *1=Enabled]
42 CompactRFTM Operating Manual: Appendix A Modem Command Summary
CompactRFTM Operating Manual: Serial Interface 43B. Serial InterfaceModem(DCE)SignalHostMicroprocessor(DTE)1 DCD →IN2 RX →IN3← TX  OUT4← DTR  OUT5 SG →IN6 DSR →IN7← RTS  OUT8 CTS →INArrows denote the direction thatsignals are asserted (e.g., DCDoriginates at the DCE and tells theDTE that a carrier is present).The CompactRFTM uses 8 pins on its 36 pin header for asynchronous serialI/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 (positivevoltage), DCD informs the DTE that a communications link has beenestablished with another CompactRFTM.RXD Receive Data - Output from Module - Signals transferred from theCompactRFTM are received by the DTE via RX.TXD Transmit Data - Input to Module - Signals are transmitted from the DTEvia TX to the CompactRFTM.DTR Data Terminal Ready - Input to Module - Asserted by the DTE to informthe modem that it is alive and ready for communications.SG Signal Ground - Provides a ground reference for all signals transmitted byboth DTE and DCE.DSR Data Set Ready - Output from Module - Asserted by the DCE to informthe DTE that it is alive and ready for communications. DSR is the modem’sequivalent of the DTR signal.RTS Request to Send - Input to Module - A “handshaking” signal which isasserted 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 isasserted by the DCE when it has enabled communications and transmissionfrom the DTE can commence. When hardware handshaking is used, theCTS 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 shouldbe kept in mind when looking at signals relative to the modem (DCE); the modemtransmits 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.
44 CompactRFTM Operating Manual: Appendix B Serial Interface
CompactRFTM Operating Manual: Appendix C. Factory Default Settings 45C. Factory Default SettingsAT&F1 - Master Default SettingsE1, Q0, V1, W0, S0=0, S2=43, S3=13, S4=10, S5=8DCD &C1 (On)DTR &D0 (DTR is ignored)Framing &E0 (Disabled)Handshaking &K3 (Enabled)DSR &S1 (On in Data, Off in Command)Operating Mode S101=1 (Master P-MP)Serial Baud Rate S102=1 (115kbaud)Wireless Link Rate S103=4 (Fast, FEC)Network Address S104=1Unit Address S105=1Primary Hop Pattern S106=0Encryption Key S107=1Output Power S108=2 (100mW)Hop Interval S109=8Data Format S110=1 (8N1)Packet Minimum Size S111=1Packet Maximum Size S112=255Packet Retransmissions S113=2Link Handshaking S122=1 (Enabled)Packet Repeat Interval S115=1 (Don’t Care)Character Timeout (ms) S116=8Modbus Mode S117=0RTS/DCD Framing (ms) S120=0DCD Timeout (ms) S121=0Secondary Hop Pattern S206=2 (Don’t Care)Packet Retry Limit S213=2 (Don’t Care)AT&F2 - Slave Default SettingsE1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8DCD &C1 (On when modems are synced)DTR &D0 (DTR is ignored)Framing &E0 (Disabled)Handshaking &K3 (Enabled)DSR &S1 (On in Data, Off in Command)Operating Mode S101=3 (Slave)Serial Baud Rate S102=1 (115kbaud)Wireless Link Rate S103=4 (Fast, FEC) (Set by Master)Network Address S104=1Unit Address S105=2Primary Hop Pattern S106=0Encryption Key S107=1Output Power S108=2 (100mW)Hop Interval S109=8 (Set by Master)Data Format S110=1 (8N1)Packet Minimum Size S111=1 (Set by Master)Packet Maximum Size S112=255 (Set by Master)Packet Retransmissions S113=2 (Don’t Care)Link Handshaking S122=1 (Enabled) (Set by Master)Packet Repeat Interval S115=1Character Timeout (ms) S116=9Modbus Mode S117=0RTS/DCD Framing (ms) S120=0DCD Timeout (ms) S121=0Secondary Hop Pattern S206=2 (Don’t Care)Packet Retry Limit S213=2AT&F3 - Repeater Default SettingsE1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8DCD &C1 (On when modems are synced)DTR &D0 (DTR is ignored)Framing &E0 (Disabled)Handshaking &K3 (Enabled)DSR &S1 (On in Data, Off in Command)Operating Mode S101=4 (Repeater)Serial Baud Rate S102=1 (115kbaud)Wireless Link Rate S103=4 (Fast, FEC) (Set by Master)Network Address S104=1Unit Address S105=3Primary Hop Pattern S106=0Encryption Key S107=1Output Power S108=2 (100mW)Hop Interval S109=8 (Set by Master)Data Format S110=1 (8N1)Packet Minimum Size S111=1 (Set by Master)Packet Maximum Size S112=255 (Set by Master)Packet Retransmissions S113=2Link Handshaking S122=1 (Enabled) (Set by Master)Packet Repeat Interval S115=1Character Timeout (ms) S116=8Modbus Mode S117=0RTS/DCD Framing (ms) S120=0DCD Timeout (ms) S121=0Secondary Hop Pattern S206=2Packet Retry Limit S213=2AT&F4 -Slave Through Repeater Default SettingsE1, Q0, V1, W0, S0=1, S2=43, S3=13, S4=10, S5=8DCD &C1 (On when modems are synced)DTR &D0 (DTR is ignored)Framing &E0 (Disabled)Handshaking &K3 (Enabled)DSR &S1 (On in Data, Off in Command)Operating Mode S101=3 (Slave)Serial Baud Rate S102=1 (115kbaud)Wireless Link Rate S103=4 (Fast, FEC) (Set by Master)Network Address S104=1Unit Address S105=4Primary Hop Pattern S106=2Encryption Key S107=1Output Power S108=2 (100mW)Hop Interval S109=8 (Set by Master)Data Format S110=1 (8N1)Packet Minimum Size S111=1 (Set by Master)Packet Maximum Size S112=255 (Set by Master)Packet Retransmissions S113=2 (Don’t Care)Link Handshaking S122=1 (Enabled) (Set by Master)Packet Repeat Interval S115=1Character Timeout (ms) S116=8Modbus Mode S117=0RTS/DCD Framing (ms) S120=0DCD Timeout (ms) S121=0Secondary Hop Pattern S206=2 (Don’t Care)Packet Retry Limit S213=2
46 CompactRFTM Operating Manual: Appendix C Factory Default Settings
CompactRFTM Operating Manual: Appendix D. Performance Tables 47D. Performance TablesThe scope of this appendix is to find the best possible performance and maximum packet size at different modes ofoperation. The setup assumes a baud rate of 115k, no retries and no retransmissions..HopIntervalOptimal Packet Size (bytes)Throughput(kbps)*1 (8 ms) 14 20Master to Slave 2 (12 ms) 66 52Communication. 3 (16 ms) 110 66(No Repeater) 4 (20 ms) 154 745 (30 ms) 255 83Link Rate = Fast 6 (45 ms) 255 56NO FEC 7 (80 ms) 255 318 (120 ms) 255 211 (8 ms) 5 4Master to Slave 2 (12 ms) 34 22Communication. 3 (16 ms) 54 28(No Repeater) 4 (20 ms) 76 325 (30 ms) 130 38Link Rate = Fast 6 (45 ms) 210 43WITH FEC 7 (80 ms) 255 308 (120 ms) 255 201 (8 ms) N/A N/AMaster to 2 (12 ms) 3 1Repeater Direct 3 (16 ms) 22 13Communication. 4 (20 ms) 44 215 (30 ms) 101 32Link Rate = Fast 6 (45 ms) 178 39NO FEC 7 (80 ms) 255 318 (120 ms) 255 211 (8 ms) N/A N/AMaster to 2 (12 ms) N/A N/ARepeater Direct 3 (16 ms) 5 2Communication. 4 (20 ms) 16 65 (30 ms) 43 12Link Rate = Fast 6 (45 ms) 80 16WITH FEC 7 (80 ms) 174 208 (120 ms) 255 201 (8 ms) N/A N/AMaster to Slave 2 (12 ms) 3 1Through One or 3 (16 ms) 22 13More Repeaters. 4 (20 ms) 43 215 (30 ms) 93 31Link Rate = Fast 6 (45 ms) 174 38NO FEC 7 (80 ms) 255 318 (120 ms) 255 211 (8 ms) N/A N/AMaster to Slave 2 (12 ms) N/A N/AThrough One or 3 (16 ms) N/A N/AMore Repeaters. 4 (20 ms) 14 65 (30 ms) 40 12Link Rate = Fast 6 (45 ms) 80 16WITH FEC 7 (80 ms) 174 198 (120 ms) 255 20
48 CompactRFTM Operating Manual: Appendix D. Performance Tables
CompactRFTM Operating Manual: Appendix E. Hopping Patterns 49E. Hopping PatternsThis Appendix provides a guide for selecting appropriate hopping patterns (S106,S206). Thereare 35 hopping patterns. Patterns have been designed to notch out certain segments of the ISMband.Pattern Number Spectrum Used0 - 4 902.6 - 922.6 MHz5 - 9 902.8 - 922.8 MHz10 - 19 902.6 - 927.4 MHz20 - 24 902.6 - 912.6 MHz25 - 29 912.8 - 922.8 MHz30 - 34 917.4 - 927.4 MHz
50 CompactRFTM Operating Manual: Appendix E. Hopping Patternss
CompactRFTM Operating Manual: Appendix F. Technical Specifications 51F. Technical SpecificationsElectrical/PhysicalData Interface Asynchronous Serial Port, TTL LevelsSignals Sig. Gnd, TX, RX, DCD, DSR, DTR, RTS, CTSBaud rate 2,400 - 19200 bps, (user-selectable)Up to 19200 full-duplex sustained throughputCommunications Range116 kilometres (10 miles)Voltage Requirements 4.75 to 5.5 VDC, 1.0 AmpCurrent Consumption Rx: 85mA;Tx 1mW: 100mA;Tx 10mW: 132mA;Tx 100mW: 231mA;Tx 1W: 600mA;Sleep: <1.5mAOperating Frequency 902 - 928 MHzSystem Gain 133 dBSensitivity -103 dBmOutput Power 1mW, 10mW, 100mW, 1W (user-selectable)Spreading Code Frequency HoppingHopping Patterns 35 pseudo-random, user-selectableError Detection CRC-16 with auto re-transmitMemory Non-volatile configuration memoryDimensions (LxWxH) Approx. 2.0” x 1.5” x 0.375”Weight Approx. 20 gramsOperating Environment Temperature: -25 to +70°CHumidity: 5 to 95%, non-condensingStorage Temperature -40 to 90°C1. Clear line-of-sight, elevated antennas.
52 CompactRFTM Operating Manual: Appendix F. Technical Specifications
CompactRFTM Operating Manual: Appendix G. Development Board Schematics 53G. Development Board SchematicsSchematics begin on next page.
54 CompactRFTM Operating Manual: Appendix G. Development Board Schematics
CompactRFTM Operating Manual: Appendix G. Development Board Schematics 55
56 CompactRFTM Operating Manual: Appendix G. Development Board Schematics
CompactRFTM Operating Manual: Appendix G. Development Board Schematics 57
58 CompactRFTM Operating Manual: Appendix H. Mechanical Drawing
CompactRFTM Operating Manual: Appendix H. Mechanical Drawing 59H. Mechanical DrawingDimensions in thousandths of an inch.Shaded areas = keep clear. Microhard Systems Inc.CompactRF Mechanical Drawing110, 1144 - 29th Avenue N.E..Calgary, Alberta, CanadaT2E 7P1Rev.2Size A Document Number: D1043-02 Drawn By: NB Sheet 1 of 1Wednesday, July 26, 200033037578.7 (2mm) 525 1245225200 50015002000dia. 648075410Top ViewPin 11819 36Recommended FootprintDrill Size = 32 mil11819 3678.7 (2mm)1245
60 CompactRFTM Operating Manual: Appendix H. Mechanical Drawing
CompactRFTM Operating Manual: Appendix I. Glossary 61I. GlossaryTerminology Used in the CompactRFTM Operating ManualAsynchronous communications A method oftelecommunications in which units of single bytesof data are sent separately and at an arbitrary time(not periodically or referenced to a clock). Bytesare “padded” with start and stop bits to distinguisheach as a unit for the receiving end, which neednot be synchronized with the sending terminal.Attenuation The loss of signal power throughequipment, lines/cables, or other transmissiondevices. Measured in decibels (dB).Bandwidth The information-carrying capacity of adata transmission medium or device, usuallyexpressed in bits/second (bps).Baud Unit of signaling speed equivalent to thenumber of discrete conditions or events persecond. If each signal event represents only onebit condition, then baud rate equals bits persecond (bps) – this is generally true of the serialdata port, so baud and bps have been usedinterchangeably in this manual when referring tothe serial port; this is not always the case duringthe DCE-to-DCE communications, where anumber of modulation techniques are used toincrease the bps rate over the baud rate.Bit The smallest unit of information in a binarysystem, represented by either a 1 or 0.Abbreviated “b”.Bits per second (b/s or bps) A measure of datatransmission rate in serial communications. Alsosee baud.Byte A group of bits, generally 8 bits in length. Abyte typically represents a character of data.Abbreviated “B”.Characters per second (cps) A measure of datatransmission rate for common exchanges of data.A character is usually represented by 10 bits: an 8-bit byte plus two additional bits for marking thestart and stop. Thus, in most cases (but notalways), cps is related to bits per second (bps) bya 1:10 ratio.CRC (Cyclic Redundancy Check) An error-detectionscheme for transmitted data. Performed by usinga polynomial algorithm on data, and appending achecksum to the end of the packet. At thereceiving end, a similar algorithm is performedand checked against the transmitted checksum.Crossover cable (Also known as rollover, null-modem, or modem-eliminator cable) A cablewhich allows direct DTE-to-DTE connectionwithout intermediate DCEs typically used tobridge the two communicating devices. Can alsobe used to make cabled DCE-to-DCE connections.The name is derived from “crossing” or “rolling”several lines, including the TX and RX lines sothat transmitted data from one DTE is received onthe RX pin of the other DTE and vice-versa.Data Communications Equipment (DCE, alsoreferred to as Data Circuit-TerminatingEquipment, Data Set) A device which facilitates acommunications connection between DataTerminal Equipment (DTEs). Often, two or morecompatible DCE devices are used to “bridge”DTEs which need to exchange data. A DCEperforms signal encoding, decoding, andconversion of data sent/received by the DTE, andtransmits/receives data with another DCE.Common example is a modem.Data Terminal Equipment (DTE) An end-device which sends/receives data to/from a DCE,often providing a user-interface for informationexchange. Common examples are computers,terminals, and printers.dBm Stands for “Decibels referenced to onemilliwatt (1 mW)”. A standard unit of powerlevel commonly used in RF and communicationswork. n dBm is equal to 10(n/10) milliwatt, so0dBm = 1mW, -10dBm = 0.1mW, -20dBm =0.01mW, etc.DCE See Data Communications Equipment.DTE See Data Terminal Equipment.Flow Control A method of moderating thetransmission of data so that all devices within thecommunications link (DTEs and DCEs) transmitand receive only as much data as they can handleat once. This prevents devices from sending datawhich cannot be received at the other end due toconditions such as a full buffer or hardware not ina ready state. This is ideally handled by hardwareusing flow-control and handshaking signals, but
62 CompactRFTM Operating Manual: Appendix I. Glossarycan be controlled also by software using X-ON/X-OFF (transmitter on/off) commands.Frequency-hopping A type of spread spectrumcommunication whereby the carrier frequencyused between transmitter and receiver changesrepeatedly in a synchronized fashion according toa specified algorithm or table. This minimizesunauthorized jamming (interference) andinterception of telecommunications.Full-duplex Where data can be transmitted,simultaneously and independently, bi-directionally.Half duplex Exists when the communicationsmedium supports bi-directional transmission, butdata can only travel in one direction at the sametime.Handshaking A flow-control procedure forestablishing data communications wherebydevices indicate that data is to be sent and awaitappropriate signals that allow them to proceed.Line-of-sight Condition in which a transmittedsignal can reach its destination by travelling astraight path, without being absorbed and/orbounced by objects in its path.Master The station which controls and/or polls oneor more Slave stations in a point-to-point or point-to-multipoint network. Often functions as a serveror hub for the network.Non-volatile memory Memory which retainsinformation which is written to it.Null modem cable See Crossover cable.Point-to-point A simple communications networkin which only two DTEs are participants.Point-to-multipoint A communications networkin which a Master DTE communicates with two ormore Slave DTEs.Repeater A device which automatically amplifiesor restores signals to compensate for distortionand/or attenuation prior to retransmission. Arepeater is typically used to extend the distancefor which data can be reliably transmitted using aparticular medium or communications device.RS-232 (Recommended Standard 232; moreaccurately, RS-232C or EIA/TIA-232E) Definedby the EIA, a widely known standard electricaland physical interface for linking DCEs and DTEsfor serial data communications. Traditionallyspecifies a 25-pin D-sub connector, althoughmany newer devices use a compact 9-pinconnector with only the essential signaling linesused 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 termdescribing a DTE device which is part of a wide-area network. Often a RTU performs data I/O andtransmits the data to a centralized station.Serial communications A common mode ofdata transmission whereby character bits are sentsequentially, one at a time, using the samesignaling line. Contrast with parallelcommunications where all bits of a byte aretransmitted at once, usually requiring a signal linefor each bit.Shielded cable Interface medium which isinternally shrouded by a protective sheath tominimize external electromagnetic interference(“noise”).Slave A station which is controlled and/or polled bythe Master station for communications. Typicallyrepresents one end of a point-to-point connection,or one of the terminal nodes in a point-to-multipoint network. Often a RTU is linked by aSlave DCE.Spread spectrum A method of transmitting asignal over a wider bandwidth (using severalfrequencies) than the minimum necessary for theoriginally narrowband signal. A number oftechniques are used to achieve spread spectrumtelecommunications, including frequency hopping.Spread spectrum provides the possibility ofsharing the same band amongst many users whileincreasing 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 communicationsystem, often expressed as bits or characters persecond (bps or cps).
CompactRFTM Operating Manual: Appendix J. FCC RF Exposure 63J. FCC RF ExposureFCC RF Exposure WarningIn order to comply with the FCC/IC adopted RF exposure requirements, this transmitter systemwill be installed by the manufacturer’s reseller professional. Installation of all antennas must beperformed in a manner that will provide at least 23 cm clearance from the front radiatingaperture, to any user or member of the public.

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