How do I set a time limit for specif Alarm generation frequencies

[Davidd]

I have a situation where there are several limit switches in the plant on various hardware that create continuous streams of alarms.  For instance, I have a 'high level' limit switch that controls filling a tank..  When the tank is filled, and the limit switch causes the pump to shut off, dsturbances in the tank will cause an alarm to occur every 5-10 seconds, as the limit switch closes and then opens in response to the disturbance.  The alarm is important, if it remains active for a period of time.  Is there a way to set the DI block so that an alarm will only occur once when the alarm becomes active?  Over time, I end up with hundreds of 'unacked', but not active alarm messages, and a single current 'active' one if the condition exists.  I'd like to only generate an alarm once, and not deactivate it unless the alarm goes off for a certain amount of time.

David Dudley

[alan g.]

Sounds like the same type of thing discussed in this thread:

http://forums.ni.com/ni/board/message?board.id=190&message.id=3035&view=by_threading&page=1

You might contact the author of that thread and see how he made out.

[butler]

Davidd,

The nuetralzone object work well for this problem. When the high level is reached, it will give you an alarm. On the reset of the alarm you can set to the alarm value minus a value the bin must drop before it resets the alarm.

If you are wanting a time delay, you can attach a timer object to the high level in the bin and then attach the alarm object to the timer. This will give you a time delay before the alarm becomes active. After the alarm is activated and if the high level switch resets itself, the timer will reset and a new alarm will be generated.

Hope this helps.

DButler

[Davidd]

We both talking Lookout here?  I don't see any way to recieve a signal when an Alarm has been Acknowledged, nor do I see any way to receive a signal when a specific alarm has gone inactive.

If there is a way, please let me know.  That is exactly what I'm looking for.

David Dudley