Campbell TX312, Instruction Manual

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TX312 Transmitter
1. Introduction
The TX312 transmitter supports one-way communication, via satellite, from a
Campbell Scientific datalogger to a ground receiving station. Satellite
telemetry offers a convenient telecommunication alternative for field stations
where phone lines or RF systems are impractical.
The TX312 utilizes non-volatile memory to store configuration information,
such as platform ID, transmission baud rate, channel number, scheduled
transmission time, offset time and message window length. The TX312 also
has a 15.7 K byte RAM buffer for scheduled transmissions and a buffer for
random transmissions. The clock is maintained with a GPS receiver.
TX312 supports the following certification standards:
•
300/1200 BPS DCPRS Certification Standard version 1.0b - March 2000
•
100 BPS Self-timed DCPRS Certification Standard - November 1981
•
100 BPS Random DCPRS Certification Standard - November 1981
•
SDI-12, A Serial-Digital Interface Standard for Microprocessor-based
Sensors version 1.2 - October 21, 1996
High data rates are supported. The TX312 includes serial communication
ports:
•
CS I/O for Campbell dataloggers
•
RS-232 port used for dataloggers and PC communication
•
SDI-12 is used where only SDI-12 sensors are used and a datalogger is not
needed
The CS I/O port is a Campbell Scientific Synchronous Device for
Communication (SDC) port.
The 21X and CR7 dataloggers do not support SDC or the
TX312.
NOTE
The National Environmental Satellite, Data, and Information
Service (NESDIS) certification of the TX312 was done for
Forest Technology Systems, Ltd. under model name FTS
TX312. See Appendix H for a copy of the certification
certificate. NOTE
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