Operational overview

PI Interface for OPC DA starts by using a Windows batch (.bat) file that invokes the interface executable. The .bat file contains command-line parameters for the interface settings.

For normal startup, PI Interface for OPC DA performs the following operations:

1. Connects to Data Archive (unless disconnected startup is configured)

2. Gets PI points from Data Archive

3. Connects to OPC server

4. Creates OPC groups

5. Adds items to groups

6. Activates groups (unless groups are created as active)

7. Begins data collection

Once data collection starts, the interface performs the following operations:

• Services scheduled input points and process each scan class in turn

• Services output points as events arrive

• Services triggered input points as events arrive

• Checks the PI point database for points that are added, edited, and deleted

• Reloads new or changed points

The interface checks for point updates every 2 minutes. The interface processes 25 point updates at a time. If more than 25 points are added, edited, or deleted at one time, the interface processes the first 25 points, waits 30 seconds (default) or one-fourth of the time specified by the UniInt updateinterval parameter, whichever is lower, processes the next 25 points, and so on. After all points have been processed, the interface resumes checking for updates at the update interval.