Configuring a module to access diagnostic data

When configuring a module to access diagnostic data, you should take into consideration the following qualifications:

• Detail Displays

  Detail displays do not have direct access to device diagnostic parameters. Therefore, to implement diagnostic data in a detail display, you must configure references to parameters in modules, which in turn reference the diagnostic parameters.

• Faceplates

  You can create faceplates for specific devices. Using the same technique used for dynamos, use the @MOD@ placeholder format in paths for datalinks to a marshalling module. In this way, a marshalling module can hide all the cryptic paths to the desired diagnostic parameters, so that all you need to do is fill in the marshalling module tag.

• DeltaV Explorer

  You can see and enter a diagnostic parameter path in parameter Properties dialogs for internal read parameters of the external reference parameter type. Renaming a device tag results in renaming the device_specifier in any external reference to diagnostic parameters for a device.

  Expressions must use external reference parameters to gain access to diagnostic parameters.

  Only the device_specifier component of the path is checked to ensure that it can be resolved. After modifying or using a diagnostic path, you only need to download the module.

  Note

  An invalid reference following the device_specifier, such as a negative number or number containing a decimal point, is not checked and no warning will indicate that it could not be resolved.

• Control Studio

  As in DeltaV Explorer, you can see and enter a diagnostic parameter path in parameter Properties dialogs for internal read parameters of the external reference parameter type. Function block expressions, SFC transitions, and step actions must use external reference parameters to gain access to diagnostic parameters.

  A module alarm cannot reference a diagnostic parameter directly. You must configure an external reference to a diagnostic parameter, and then reference the external reference parameter in the alarm properties.

• Bulk Edit

  You can enter device diagnostic paths for external reference parameters using standard DeltaV bulk edit tools.