How to create alarms for OPC points


If the points of 3rd party system are integrated into Vista through OPC, how to create Vista alarm for these points?

Product Line

TAC Vista





Sometimes OPC points also need to trigger alarms in the system.


  1. Create a Change of State object for the point that needs to trigger alarm.
  2. In the Alarm tab, choose the alarm control for this alarm, while type the Text for tripped alarm and reset alarm. For analog value, alarm Low limit, High limit and Minimum change can be set for the triggering boundary. For digital alarm, just keep the default setting for the limitation setting. 
  3. In the Object tab, choose the signal that needs to trigger alarm. And also select the Referenced property to "Value".
  4. Open the Property window of the signal and set the Watch Setting to "Alarm" or "Watch".
  5. Toggle the OPC point manually into alarm and return to normal once to verify the alarm is in the queue.
For specific setting for I/NET points integration, refer to Lessons Learned Article #4571 for detailed information.