Applies To:
  • CitectSCADA 5.xx

Sometimes I have a system error message :

ERROR-file ( I:\Cit521\spkB\source\api\dll\SYNC.C)(line 111) - Deadlock detected

What is causing this error message?


This error message is used to detect possible deadlock conditions in the CTAPI interface. The CTAPI interface will send requests to Citect for processing and wait for the response. If the response does not occur within the deadlock detection timeout period you will get this error message. Normally CTAPI commands execute very quickly and you should not get this error message. However you can execute cicode queries or request large amounts of alarm/trend data which exceed the deadlock timeout period. In version 5.0 the deadlock timeout was set to 1 minute. This timeout has been increased to 5 minutes in version 5.30 to allow longer queries.