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v13 PCSD SIS BMS Alarm Philosophy


I have been reviewing the BMS demo that came with PCSD v13.3.1 D and have noticed that the "shadow" modules seem to have gone away. While I'm interested in this concept, I can't seem to find where the individual trip condition alarms have gone. By this, I'm referring to the pre-trip and trip limit indications. The demo only has bypass, bad i/o, and master trip alarms.

I suppose, as a more general question, what is the alarming philosophy being followed in this demo?



2 Replies

  • Hi Dave,

    As you probably know, with BMS systems many of the trips are conditional to the active phase of the BMS sequence. For instance a low flow on the purge air is an issue when purging but of no consequence when the pilot or main burner is lit.
    Secondly, once a trip condition activates and trips the burner then most often that condition is no longer an issue once tripped.
    Thirdly, we'd like to avoid alarm floods and rationize the alanrs as much as possible.

    So, the basic approach is that we don't alarm the individual trip conditions since this would require a lot of conditional logic. Instead we have a common alarm which indicates that the burner tripped. In the demo clicking this alarm will take you to the graphic which shows you all the possible trip causes. This graphic will indicate which device is tripped. Clicking on the "up" arrow will take you to the sequence graphic where the first out dynamos will then tell you what caused the trip. Obviously you can easily change this around as you wish in your own application by simply defining the primary graphic differently.
    We feel that this approach with a common trip alarm is one that best meets all the above mentioned criteria and is also operationally sound. The key issue is the fact that the burner tripped and then you want to know why but the why doesn't need to be an alarm on its own.

    As for shadow modules, in PCSD for SIS v13 we introduced a new approach. For various reasons we had to move away from the shadow modules. One key reason was that we wanted to provide you with a similar experience as regular DeltaV. So instead of the shadow modules we now have Data Modules which only contain a few parameters. Note that in v14 this will be replaced with the product inherent alarm groups and you will no longer need any extra modules at all.
  • In reply to Rafael Lachmann:

    Hi Rafael,

    Thank you for the detailed write up, that clarifies a lot!