ACM Is Polling For Too Much Data

ACM data polls are executed for many reasons. If you believe ACM is polling for more data than it should, the following environment or configuration settings may be the source of the polling. 

• ACM polls for client applications that are connected with “advised” items. This is normal behavior. Check these applications to see if they have unnecessary items in their configuration. Examples of client applications are HMI programs, Historians, and custom “API” programs. These applications can connect to ACM in the following ways:

  • OPC DA

  • OPC UA

  • ACM API

• ACM polls items if its configuration contains Alias Group objects configured with the options “Auto Poll” or “MQTT” enabled. Disable these options if the item data is not needed.

• ACM polls for diagnostic items on open Device or Connection configuration forms.

  • Check the “Options” tab on these forms to see if diagnostic items are configured. Remove the item names from the configuration if they’re unnecessary. Note: These items are only polled when the configuration form is open.

  • Check the “Status Viewer” on these forms to see if there is an Alias Group object selected. Items in the selected Alias Group are polled if the User Preference option “Activate Alias Tags on Status Tab” is set to “Always” or if it is set to “Only When Alias Group Tags Are Active” and the selected Alias Group’s “Auto Poll” option is enabled. If polling for the “Status Viewer” is unnecessary, change the User Preference option to “Never”.