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EWAVE Inc.

7419 Gracefield Ln.
Dallas, Texas 75248
(972) 248-2931

www.electrowave.com

Ewave Radio Modem Technical Manual

Version 1.02

Ewave Radio Modems covered in this manual:

SuperSCREAMER

BaseWAVE

SCREAMER 422

STAMPER

Summary of Contents for BaseWAVE

Page 1: ...Inc 7419 Gracefield Ln Dallas Texas 75248 972 248 2931 www electrowave com Ewave Radio Modem Technical Manual Version 1 02 Ewave Radio Modems covered in this manual SuperSCREAMER BaseWAVE SCREAMER 422 STAMPER ...

Page 2: ...AVE RADIO MODEM PROTOCOL CONFIGURATIONS 10 3 8 COMMAND STATE VS DATA STATE 11 3 9 THE SUPERSCREAMER WITH DYNAMIC PROTOCOL SUPPORT 12 4 COMMANDS 13 4 1 QUERY SETTINGS 13 4 2 QUERY VERSION 13 4 3 QUERY STATION TYPE 14 4 4 SET MODE OF MODEM ENHANCED SCREAMER ONLY 14 4 5 ATTENTION ON OFF 14 4 6 TX POWER ON OFF 15 4 7 RETRY ON OFF 15 4 8 SET CHANNEL 15 4 9 SET PACKET SIZE THRESHOLD 15 4 10 SET WAIT TIM...

Page 3: ...ike a serial cable to your application Transparent protection from errors and interference via 16 bit CRC Cyclic Redundancy Code optional High data reliability via transparent automatic Retry Acknowledge optional Dynamic packetization of data providing low latency while maintaining high throughput Packetization configurable via software parameters Maximum Packet Size Threshold and Next Byte Wait T...

Page 4: ...lso available which includes all the above Protocol features in one Modem and allows software feature selection on the fly Supply Voltage 5VDC supply voltage 3 3VDC also available 140mA 7 2 10VDC supply voltage unregulated 140mA Packaging Industrial strength ABS case OEM module without case ...

Page 5: ...ation requirements for the Ewave Radio Modems however for best performance the modems antennae should be oriented parallel to each other and perpendicular to the ground Please refer to Ewave s On line Support Center at http www electrowave com support shtml for help with installation or troubleshooting problems ...

Page 6: ...imultaneously To allow full duplex operation the Base and Mobile units contain matched pairs of the Ewave RF transceiver module which are optimized to transmit on a different range of frequencies e g the Base units transmit on 926 928 MHz while the Mobile units transmit on 902 904 MHz The exact frequencies for each channel are listed in the appendix Note that it is possible to implement various mu...

Page 7: ... the pin out for the SCREAMER 422 3 3 LEDs The table below summarizes the meaning of the Ewave Radio Modem s LEDs What it means Status LED Transmit LED Receive LED Modem is in Command state Rapid Blink TX Power is On ON TX Power is Off Modem in command state Rapid Blink OFF TX Power is Off Modem in data state ON OFF Modem is Actively Transmitting Data OFF FLASHING Modem is Actively Receiving Data ...

Page 8: ...nchronous serial data In comparison to a hard wired connection there are several important issues to be aware of when using the Ewave Radio Modems Latency bandwidth and errors 3 5 1 Latency Latency or delay is the time between an action and a response e g the time between when a byte is sent and when it is received by the other modem With a hard wired electrical connection the latency is very smal...

Page 9: ...ate to compensate for the aforementioned overhead The Ewave Radio Modem transfers data over the air at approximately 10 000 bits second 3 5 3 Errors Errors and interference are much more common in a wireless communications system compared to a wired one The effect of this is to increase latency and decrease bandwidth For instance if the Ewave Radio Modem is programmed for automatic retry acknowled...

Page 10: ... Modems can implement an automatic Retry Acknowledge scheme which is transparent to the application This combined with CRCs for error detection greatly improves the reliability of data transfer without requiring any changes to the application However note that in this mode depending on the level of interference data may be delayed for arbitrarily long times Applications which implement their own p...

Page 11: ...ied settings in EEPROM The settings which may be changed depend on the protocol configuration of the Ewave Radio Modem The default factory Baud Rate is set to 9600 N81 Whenever the modem enters Command state or whenever the modem processes a valid Command it sends a response of OK followed by a CR LF While in command state Radio Data reception is disabled Invalid commands result in a response of E...

Page 12: ...ttention ON Command state may be entered by simply asserting RTS De asserting RTS returns the modem to Data mode and Command state may be re entered any number of times by re asserting RTS 3 9 The SuperSCREAMER with Dynamic Protocol Support Regular Ewave Radio Modems are pre programmed at the factory with firmware specific to their expected use The Enhanced SuperSCREAMER includes support for all p...

Page 13: ... the Dx commands which update EEPROM should execute within 5 milliseconds plus whatever time is required to transfer any response in the case of the QUERY commands which varies depending on the current modem baud rate setting The Dx commands should execute within 25 milliseconds 4 1 QUERY SETTINGS Send Modem responds with a human readable summary of its current settings Every line ends with a CR L...

Page 14: ...rejects packets with invalid CRCs The maximum data throughput when using Checksum mode is 964 bytes second Mb Break mode Used with Parallax parts generates RS232 Break and RTS to CTS outputs Break mode is used in applications that need to be able to send a serial Break signal and also send and receive RTS CTS hardware handshake signals This mode is useful when using the Radio Modem to program and ...

Page 15: ...mmand Channel Char in Decimal Channel Char in Hex 4 0x04 C4 52 0x34 13 0x0D C 61 0x3D 22 0x16 CF 70 0x46 31 0x1F CO See letter Oh 79 0x4F 40 0x28 CX 88 0x58 Both modems must be on the same channel to communicate 4 9 SET PACKET SIZE THRESHOLD Send Px where x is 0x31 0x58 Set the size threshold for data packets How this parameter is interpreted depends on the modem s protocol configuration For RM200...

Page 16: ...6 possible values are valid wait times Example If the modem s serial port is set to 9600 baud then it takes about 1 04 ms for a byte to be shifted into the modem s serial port If the delay between bytes being sent to the modem s serial port is 5 ms then setting a Wait Time greater than 5 0 ms 1 04ms 6 04 ms will result in these bytes being grouped together into maximally sized packets Conversely i...

Page 17: ...TX power on Current A 100 mA TX Power off Sustained Data Rate 9600 baud or 1071 bytes sec Burst Data Rate 38 4 K baud Channels 1 to 40 depending on version Channel Spacing 50 kHz Range 300 feet typical Output Power 50 000 uVolts meter at 3 feet max Frequency MHz Base Mobile Tx 926 928 902 904 Rx 902 904 926 928 Modulation 8 0kHz Temperature 50 110 F ...

Page 18: ...93 12 902 632 926 544 13 902 682 926 594 14 902 732 926 644 15 902 782 926 694 16 902 833 926 745 17 902 883 926 795 18 902 933 926 845 19 902 983 926 895 20 903 033 926 946 21 903 084 926 996 22 903 134 927 046 23 903 184 927 096 24 903 234 927 147 25 903 285 927 197 26 903 335 927 247 27 903 385 927 297 28 903 435 927 347 29 903 486 927 398 30 903 536 927 448 31 903 586 927 498 32 903 636 927 54...

Page 19: ...http www electrowave com 8 OEM Options Should our standard Ewave Radio Modem product line does not fit your needs Ewave Inc can provide custom OEM solutions We have the design capabilities to do unique board layouts features and packaging Contact us at 972 248 2931 or email oem electrowave com We will be happy to discuss your design needs and provide a price quote ...

Page 20: ...ave Radio Modem User s Manual V1 02 Copyright 2001 by Ewave Inc 20 9 Revision History February 11 2001 M Shepard Initial revision May 18 2001 PSA Release V1 01 August 3 2001 MNS Release V1 02 three typos ...

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