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

Apollo

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.

cechurat

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

Apollo

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.

cechurat

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

Apollo

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)

cechurat

Hi Kris,

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

interactive changing of the levels
disabling execution of the function block using SRTF (see doc: https://www.rexygen.com/doc/ENGLISH/MANUALS/BRef/SRTF.html#x19-180002)

Cheers,
Tomas

Apollo

@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