Troubleshooting Calculation collector

About this task

If you observer errors with Calculation collector, you should:


  1. Examine the collector log files in the Historian\LogFiles folder and scan for errors in the log that may explain your problem.
  2. Check the connection to the source.
    For example, if you lose connection to the source, all tags for that collector stop collecting. What that means is that even if you hard-code the formula results, the collector will not collect them. If you enter a formula such as result=7 on a polled, 1-second tag in the Server-to-Server Collector, Historian does not log any raw samples to the destination computer. This action occurs even though the result is hardcoded.
  3. Ensure that you are following the guidelines described in General Guidelines for Designing a Calculation Formula.
    Tip: use the LogMessage function to include messages in your formula when certain points of a calculation executes so that you can isolate errors. Refer to Writing Messages to the Collector Log File for Debugging Purposes for details.