User's Manual
Table Of Contents
- IMPORTANT NOTICE
- RESTRICTIONS ON USE
- PRODUCT CONFORMITY
- WARRANTY AND SAFETY INSTRUCTIONS
- TABLE OF CONTENTS
- INTRODUCTION
- 1 TECHNICAL SPECIFICATIONS
- 2 OPERATING VOLTAGE
- 3 SERIAL INTERFACE
- 4 USER INTERFACE
- 5 RF INTERFACE
- 5.1 Transmitter
- 5.2 Receiver
- 5.3 Priority RX/TX
- 5.4 Error correction
- 5.5 Error checking
- 5.6 User data whitening
- 5.7 Pacific Crest and TRIMTALK compatibility
- 6 TRANSPARENT DATA TRANSMISSION
- 7 SETTINGS
- 8 SW-RELATED COMMANDS AND OPTIONS
- 9 ACCESSORIES
- 10 APPENDIX A
- 11 APPENDIX B
SATELLINE-M3-TR1
User Guide, Version 3.0
16
3.4 RS-485/RS-422 interface
3.4.1 RS-485 interface
RS-485 is an extension of the RS-422 standard and enables the connection of more than two
devices on to the same bus. Communication is half-duplex, so there is only one cable pair,
compared to two when using the RS-422. The RS-485 standard defines the electrical
characteristics of the connections in such a way as to prevent possible data contention states as
well as cable shorts etc. from harming the devices themselves. To enable RS-485 function set the
modem must be ordered with RS-232/RS-422 Interface. When RS-485 is used the RS-422 on
Port 2 must be ON.
Typical RS-485 connection.
TR1 NARS-2-4A
RS-422 to RS-485 using NARS-2-4A-adapter.
Port 2
=RS-422
RS-485
Termi-
nal
Termi-
nal
Termi-
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Termi-
nal
120
120
Radio modem