Screen tag values

When you screen tag values, AVEVA Process Simulation analyzes the quality status for each tag and updates the Screened Value data in the External Data Manager. When you set the model variables to the tag values, the software uses the Screened Value data instead of the direct Tag Value data to avoid updating the model variables to tag values of bad quality.

If the quality status for a tag is good (green Quality badge) or questionable (yellow Quality badge), the software updates the Screened Value to the current Tag Value.

If the quality status for a tag is bad (red Quality badge), the software updates the Screened Value according to the If Bad Quality selection.

The Screened Value data in the External Data Manager always appears in the internal units of measure (UOMs). You may need to convert a Screened Value to accurately compare it to a Tag Value or Sim Value. See Internal units of measure for more information.

Screen tag values

1. Open the External Data Manager.

2. Select the tag collection that contains the tag values that you want to screen, and then select Transfer.

   The Read/Write External Data window appears.

3. In the Tag List section, in the If Bad Quality list for each tag, select the action that the software should take if the tag has a bad quality status.

   • Do Nothing: Leave the Screened Value blank and do not update the value of the associated model variable when you set the model variables to the tag values.

   • Use Last Good Value: Set the Screened Value to the Last Good Value and update the value of the associated model variable when you set the model variables to the tag values.

   • Report Error: Leave the Screened Value blank and do not update the value of the associated model variable when you set the model variables to the tag values. In addition, the system logs an error, but currently does not display the error in the Log pane.

4. In the Input Processing area, select Screen.

   Values in the Screened Value column update according to the quality status of the tags.