Adjust the Configuration of any Points that Cause a High Load

A possible cause of deficient performance on a ClearSCADA system is that of inadequate client performance (see Diagnose Client Performance Problems in the ClearSCADA Guide to the Server Status Tool). One of the causes of inadequate performance is high load on the server.

You can use the statistics that are shown in Lists and Status displays to identify any Generic Modbus controllers that are causing a high loading on the ClearSCADA system.

For those controllers that have a high load, use the Points List to identify the point(s) that are causing the high load.

High load is typically caused by a point updating at too frequent a rate.

1. Check the Retrieval Interval that the point is using (see Configure Common Point Properties). If this is causing the server to update the current point value at too frequent a rate, you might need to:
   • Specify a different Retrieval Interval.

     or:

   • Specify a less frequent Normal or Promoted Retrieval rate (see Define the Data Retrieval Intervals).
2. If the point is on a controller that has a direct connection to the server, check the Scan Group (Confidence Interval) that the point is using (see Configure Common Point Properties). If this is causing the server to update the current point value at too frequent a rate, you might need to:
   • Specify a different Scan Group.

     or:

   • Specify a less frequent scan rate for the Scan Group (see Define Intervals for Timed Current Data Updates in the Guide to Advanced Drivers).
3. If the point is an Analog point, ensure that the Significant Change feature is enabled (see Define the Criteria for a Significant Change in Value in the ClearSCADA Guide to Core Point Configuration).
4. If the point is an Analog point with Significant Change enabled, you might need to increase the Significant Change deadband—the amount by which the point value has to change in order for the value to be updated in the ClearSCADA database (see Define the Criteria for a Significant Change in Value in the ClearSCADA Guide to Core Point Configuration).
5. If fleeting changes in value are causing a high load, you might want to increase the Persistence settings for the point (see Use Persistence to Stop Fleeting Changes in Value from Changing a Point State). However, a sudden increase in momentary changes in state might indicate an abnormal condition elsewhere. If this occurs, check the controller, plant, and instrumentation to see whether an underlying hardware problem is causing the sudden increase.
6. If none of the above checks and configuration changes have cleared the high load caused by the point, check the following equipment for any faults:
   • Controller hardware
   • Plant
   • Instrumentation.