How to Monitor Communication Deadlocks


A panel is online, but it is not polling any events. It is possible that the COM port is deadlocked. 


To resolve this issue:
  1. Stop the Communication Server.
  2. Add the following settings to the ACS.INI under the [CommunicationServer] section:
    • MonitorComPortThreads=1
    • DeadlockDetectionThreshold=120
  3. Restart the Comm Server.
The DeadlockDetectionThreshold value above indicates the amount of time (in seconds) that must elapse without receiving an update from a Com Port Thread before the COM port is declared to be deadlocked.
If the COM port is deadlocked, the following alarms may appear:
  • Communication Thread Blocked: When communication to the panel is blocked and no events are reported to Alarm Monitoring or logged in the database.
  • Communication Thread Active: When normal communication resumes.
Right-click on the alarms for additional information about the failure.

Applies To

OnGuard (All versions)

Additional Information