Setting the Table Scan Rate

The host system polls the RTU tables at regular intervals. This confirms that site communications are working, and copies tag data from the RTU to the host database. The polling interval is configured by setting the Scan Ratefor each table in the Data Sources module. The default value is once per day.

How does the scan rate determine the polling frequency?

The polling frequency for a table is determined by two factors:

• The scan rate of the table
• The number of tables at a site with the same scan rate.

All tables at the site with the same scan rate are allocated to a group. That group of tables is scanned one at a time, at the specified scan rate. So the polling period of a table in seconds is given by its scan rate multiplied by the number of tables in the group.

To set the scan rate for a table:

1. In the Data Sources module, navigate to the table whose scan rate you want to set.
2. Click Edit to display the table properties and enable editing.
3. Set the Scan Rate in seconds.
4. Click Save to save your changes.