Campbell Scientific SDM-IO16 16-Channel Input/Output Expansion Module - Manual (Page 41)

Appendix B. Command Code Listing
Command Action
97
Set interrupt mask of ports 1-16 from 1 location. The location is a 16 bit
decimal representation from 0-65535
98 Set interrupt mask of ports 1-16 from 16 locations. The first location is port 1
and the mask is represented by 0 or 1
99 Read the OS signature, OS version and counters for watchdog resets and
communication errors into 4 locations. Using this command also resets the
counters.
B-3