Campbell Scientific SDM-SIO4 4-Channel Serial I/O Interface - Manual (Page 77)

B-1
Appendix B. Serial Port Data Transfer
Modes
This appendix describes the serial port set-up in some detail. Please note that the
numerical option codes vary between the command line set-up and the datalogger
command set-up. The ones listed below are those for the command line mode.
B.1 Baud rates
The SDM-SIO4 ports can support 16 baud rates if set up from the command
line but only 9 are available from datalogger set-up using SDM commands. An
asterisk indicates not available in SDM command mode:-
0.
57600 baud *
1. 115200 baud *
2. 25 baud *
3. 50 baud *
4. 75 baud *
5. 110 baud *
6. 150 baud *
7. 300 baud
8. 600 baud
9. 1200 baud
10. 2400 baud
11. 4800 baud
12. 9600 baud
13. 19200 baud
14. 38400 baud
15. 76800 baud
If the baud rate is higher than 9600 on two or more ports the
SDM-SIO4 may not be able to reliably collect data when there is
a lot of simultaneous input activity of more than 16 bytes without
delays. This limitation can normally be overcome by careful
planning of when data is requested from the RS232 devices, by
keeping data to less than 16-byte blocks at full speed, or by using
delays between characters. Please contact Campbell Scientific for
further advice.
B.2 Stop Bits
The number of stop bits can be set to 1, 1.5 and 2.
0. 1 stop bit
1. 1.5 stop bits if 5-bit data length or 2 stop bits for all other data lengths.
B.3 Data Length
The data length can be set from 5 to 8 bits.
NOTE