Emerson Exchange 365

• Not Answered

Excluding Control Module from Event Chronicle/PHV

Is it possible to exclude a specific module or parameters in that module from being logged or displayed in the Process History Viewer? I know with the filter, you can include specific control modules, but there doesn't seem to be a way to easily exclude a module.

I ask because I have a script running in DeltaV Operate that frequently writes to parameters in a control module which is logged in PHV as a User Change. These quickly clutter up the PHV. Any help would be appreciated. Thanks.

• Process history View
• PHV
• event chronicle
• DeltaV

JoshC

• 1 Feb 2017 2:02 PM
• Cancel

3 Replies

• Matt Forbis

  

  • 1 Feb 2017 6:19 PM

  Events are collected based on assigned process area. You could move those modules to a separate process area. The downside is that you would also lose any alarms that might be on those same modules. There is not any current functionality to be able to define what alarms and events and collected and what are not. The question I would ask is does the logic you are running really need to be in a script in the graphics? the problem with logic running in ifix is if something happens to that workstation, it no longer will execute.

  • Cancel
• Andre Dicaire

  

  • 2 Feb 2017 12:08 AM

  The supported approach to programmatic manipulation of control modules would be to either place that logic in a control module, or use an external program via OPC. The OPC server does not log writes to module parameters by default, though this can be enabled if such writes need to be recorded.
  
  Matt makes a good point that running logic in the graphics to manipulate control module can be problematic, especially if there are multiple consoles that end up running the logic under different conditions. Not capturing those writes leaves you with no record of whether the sequence performed as expected. Any such writes should be done by exception, emulating the actions of an operator.
  
  There is no way to segregate events from a module such that some are recorded and others not. As Matt states, you can only segregate events by module through their Area assignments.
  
  The recommended approach is to move the sequence logic to a control module, and then use the VB commands to manage the sequence, not every write. This provides some tracability of when the sequence fires, but not all parameter writes are recorded.
  
  If you don't record the sequence writes, you will also not record manual writes to those parameters. This will create a situation where an Operator could act on a parameter that results in unexpected or unwanted process upsets, and there would be no record of the initiating event.
  
  There are clever ways to bypass the recording of writes, but in the end, any write from a VBA script means a user on that station can also write manually without a record being generated.

  Andre Dicaire

  • Cancel
• JoshC

  

  • 7 Feb 2017 12:41 PM

  Thanks for the feedback. I'll probably move the control module to an excluded an area. The reason I am using the scripting is that this is for a plant call-out system that should only activate on high priority alarms. There were only a few ways I could think of to make this work and I decided that using the alarm banner was the easiest and most straightforward. In order to do that it has to be done through Operate using scripts.

  • Cancel