Searching Dynamic References in DeltaV PCSD Library

Why are dynamic references used throughout the DeltaV PCSD library (especially in the PID class modules) without Emerson providing a way to easily search online references?

Discuss.

3 Replies

  • Hi James, what I've done in the past is use the DeltaV Add-in for Excel to search for online values using OPC. You can create a list of all the PCSD modules that use Dynamic References and read the .$REF parameters. This will show you what parameters are being referenced. It takes a little setup, but can be very useful during troubleshooting.
  • I think there are two topics here:

    1. Why PCSD uses Dynamic References

    There are numerous reasons why it's done this way:

    • Blank External References aren't supported without generating download errors
    • Being able to add a master loop later that didn't require module class changes at an instance
    • Showing what the Master Loop is on the Faceplate of the Slave
    • Showing what the Slave Loop is on the Faceplate of the Master
    • Dynamically changing who the master loop is (I have never done this and also suggest that this never done but this was a requirement at some point in the past)

    2. Why the product doesn't list list dynamic references when you do references on a module

    I wish I had an answer here but there is also other things that references doesn't catch either (i.e. Unit Alias resoluion and then phases that use these aliases). Hopefully in a later product release this will be fixed, I know that I have commented on this and maybe the UDEP has this already as well (I suggest submitting this to UDEP if it is really important to you as this does seem to drive some changes quicker). Here is the site to submit this or any idea you may have http://www.userideas-emerson.com.

    Now to the good news!

    PCSD v13a will NOT use Dynamic References in any place because the product has changed that allows External References to be 'ignored' and no configuration error is generated if not being used. Below is a screen shot of what it might look like for a PID:

    Regards,

    Matt

  • In reply to Brian Crandall:

    I use the add-on for other things, but can you elaborate on what I need to do to check a dynamic reference. I have something somewhere in my system that is writing on output of 100% to a specific PID controller when it is in Man mode. It is a CAS slave and also a CAS master for a downstream speed controller. Can't override it any way other than changing the OUT Limit. It works fine in CAS or Auto, only does it in MAN. No where in our configuration can we find a reference or a module that should be doing this. We get around it, by putting the slave in MAN to control the output, but it "freaks out" the operators a little, and I really can't blame them. I have searched my FHX export to no avail, so we think it is a dynamic reference doing it. Thanks in advance for your help!