ALB, ALBI, ALN, ALNI , .... alarm functions have no delay function



  • Would it be possible to create a delayON and delayOFF function for the alarm function blocks?

    I'm trying to make a workaround but this is quite cumbersome if you want to use all the other benefits of using the alarm blocks, especially for analog values.



  • Hi Kris,

    please, can you provide more details? What is expected/wanted behaviour?
    If I understand correctly you can connect TIMER FB with ALB(I) input and it should do the trick, right? Analog values can be a bit tricky...

    Kind Regards,
    Tomas



  • Hi Tomas,

    If you have for example a fluctuating analog signal or a signal with peaks it might happen that the alarm is triggered for a very short time. This behavior is perhaps completely normal and you don't want it to trigger an alarm if the signal is not too high/low for x seconds.
    Or a low-level float in a gearbox to detect low oil level on a ship requires some delay, otherwise, it would regularly trigger an alarm when there is some bad weather ... 🙂

    For boolean type signals it isn't really a problem to add some logic but to keep all function blocks for the alarming alike it would be better to implement it also for the boolean ones.



  • Hi Kris,

    thanks for youe explanation - now I understand correctly. I have generated a feature request for our developers.

    For now - did you try to apply some filtering to your measured signal? E.g. moving average filter (AVG) or SPIKE filter.

    Kind Regards,

    Tomas



  • I haven't tried filtering yet, this could work but is more complex then just a simple delay (ON&OFF).
    I have another related question. For the FB ALB, ALBI there is a 'men' input so you can disable the alarms. This feature is missing on the FB ALN, ALNI.

    Example: if you want to monitor the oil pressure from an engine it should be possible to disable/suppress the low pressure alarm while the engine is starting up and in shutdown as well.

    You have any idea how to solve this? I tried with setting parameter lvl1 to zero but this is not allowed (nor lvl 2, as described in the documentation)

    35e70244-f521-4d71-bb13-d4689e7d1cd8-image.png



  • Hi Kris,

    I have turned your post into feature request again. There are some possible workarounds:

    Cheers,
    Tomas



  • @cechurat said in ALB, ALBI, ALN, ALNI , .... alarm functions have no delay function:

    • interactive changing of the levels*

    Do you mean to set the parameters lvl1 and lvl2? Because when I do, I get the error message as described above.

    Maybe I'll try the SRTF solution, could work.... or wait for a new version with the new feature 🙂

    Grtz,

    Kris


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