Log Interval

The Log Interval defines the frequency of sampling for each tag in the group. The interval options are On Event, 2 seconds, 5 seconds, 10 seconds, 30 seconds, 1 minute, 5 minutes, 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours. If you select On Event, you must define a True or False Boolean expression. Use the Expression Editor to create a True or False Boolean expression using any tag in the process model. Each time the expression is true, the data values for each of the tags in the group are logged.

For more information on building expressions, see "Expression Editor.".

Configuring a Log Trigger and a Log Interval

You can configure a Log Trigger and a Log Interval for a process group. Logging takes place only when the trigger and interval settings are satisfied.

To select a log trigger and a log interval

1. Open the Process Logger Group Editor dialog box.

2. In the Log Trigger list, click On Event.

3. Click Expression to open the Expression Editor.

4. Enter an expression. In this example, the Boolean expression, {ReactorA...BATSZ.Value}>1000, initiates logging when the batch size in ReactorA is greater than 1000.

   

5. Click OK to close the Expression Editor.

   The expression that you entered appears in the expression box of the Process Logger Group Editor.

   

6. In the Log Interval list, click an interval.

7. Configure the log interval by repeating repeat steps 3 through 5.