What does the communications watchdog in the 831-INT-ET do?

Communication Watchdog Overview

The Model 831 and 831-INT-ET have features to monitor the USB communication between the two devices and if there is no communication for one hour, the Model 831 and 831-INT-ET will automatically power cycle.

Requirements for this feature

• 831 firmware V2.11 or later
• 831 board revision D or later
• 831 run mode = Continuous
• 831-INT-ET firmware V1.0 or later

Communication Watchdog Description 

When an 831 matching the requirements above is placed into an 831-INT-ET, the 831-INT-ET automatically sends a command to the 831 that enables the communication watchdog.  When an 831 is removed from the 831-INT-ET, the communication watchdog remains enabled but becomes inactive.  To disable the watchdog, go to Tools -> Communication -> Status and uncheck Communications Watchdog at the bottom.

If the communications watchdog triggers a power cycle, the system will turn completely off and in approximately 1-2 minutes turn back on.  A communications watchdog event produces records in the 831 Session log that show a stop due to IO and a run approximate 1-2 minutes later.

WARNING:  The 831 does not differentiate between an 831-INT and 831-INT-ET.  If an 831 has been placed in an 831-INT-ET and then later removed and placed in an 831-INT, the communication watchdog must be manually disabled.  Failure to do this will cause the 831 to turn off after one hour.

For additional information, see 831 Manual page 12-24.