800F Freelance M_ANA block alarm delay
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Hello bhjp,
If You want to delay the alarm You should add some logic before monitoring function block, not after. Delaying SL signals does not delay the alarm on Operator Station.
From Your comment I understood that the problem is quality of monitored variable. If that's the case You have multiple ways to achieve what You need.
1. Filtering - use Delay function block with proper time constant. This adds first order inertia to your signal and will work as filter for high and low peaks and noises. The drawback is that it works on the whole block - if You need another alarm to go on/off fast, You will need two monitoring blocks - one with filtered IN signal and one without filtering.
2. You may use Lead/Lag function block instead of Delay. When properly parametrized it should work as an even better filter.
3. You may use Standard > Comparator > Greater then block with timer TON and binary monitoring M_BIN instead of M_ANA block. This will only activate alarm after compared signal is greater then set value for set amount of time. This one has the drawback of using 3 or 4 FBs (if you use constant for setting up alarm value) for only one alarm.
I'm sure there are many other ways to do it, but this are three from top of my head.
Hope it helps,
Mike
Answers
Greetings
what do you mean by alarm delay?
do you want to double check the alarm to be sure it is confirmed signal not spike or something ?
if that is th case, i thing adding a time delay timer in the traditional way will be suffecent
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