Campbell Scientific CSAT3 CSAT3 3-D Sonic Anemometer - Page 57
Appendix B. Serial Communications, with the CSAT3
View all Campbell Scientific CSAT3 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 57 highlights
Appendix B. Serial Communications with the CSAT3 B.1 CSAT3 RS-232 Commands The CSAT3 powers up its RS-232 drivers when it detects that the RTS (request to send) line has been asserted by the PC. All RS-232 communications begin with the PC asserting the RTS line, the CSAT3 responds by asserting the CTS (clear to send) line. The PC must keep the RTS line asserted as long as it is communicating with the CSAT3. RS-422 communications and short-haul modems do not include an RTS signal. The CSAT3s RS-232 drivers can be asserted by a software setting in the CSAT3. This setting will always power the RS-232 drivers, independent of the RTS line. The unprompted output mode (TABLE B-1) complicates anemometer data processing software, because the original output format contains no fixed pattern to delimit the CSAT3's 10 byte output record. To configure the CSAT3 to output 12-byte records, with the last two bytes being a fixed pattern of AA55 hex, send an "rs n", where n = 0 (default) means no synchronization code and n = 1 means send the synchronization code, to the CSAT3. As is customary in the DOS environment, 55 hex is transmitted first followed by AA hex. This configuration will be lost if the CSAT3 power is cycled. To save this configuration into non-volatile memory, issue the "sr2718" command (See Section 12). There are nine commands that may be sent to the CSAT3 over the RS-232 interface. These commands are described below. Before continuing on, read the section that describes the CSAT3 Trigger (Section 8). B-1