Logix 5000 ALMD

[The Plc Kid]

I want to use the ALMD and ALMA structures for a new project but i want to see if anyone knows of a easy way to recycle a silenced alarm?

Meaning if i have a Fill level that is at its high point and the alarm activates but then the operator does not check the tank and just recycles the alarm in want to make it reinable if the fault has not been cleared in 2 minutes.

Keep doing this until the alarm is cleared. To go over the top it would be nice to also limit how many times you can silence the alarm without it being cleared.

I hate to use these canned instructions to clean up the program then throw a lot of other logic in to do this.

Is there a simple way?

 

[rdrast]

Sorry, I know of no built-in way to do that, but one method might be to create another ALMD instruction which is triggered by the .InAlarm and .Acked bits of the one you want to recycle, and set a minimum duration to 2 minutes.

You can have the secondary alarm set for a higher priority, more direct message, etc.

The only other method would involve a timer triggered off of the .InAlarm and .Acked bits to simply clear and re-trigger the alarm.

In that case, you could read the .AlarmCount field to see how many times it has been re-triggered. Of course, you would need to manually clear the .AlarmCount field when the actual alarm condition goes away.

 

[tallanwt]

how to enable/disable ALMD? Syntax <ALARM>.Disabled doesn't work. Have only been able to disable alarm from Configuration of ALMD only. I need to control from ladder logic.

 

[ASF]

Welcome to the forum! You're probably better off to create a new thread for what is a question only vaguely related to the original post, and 5 years old.

That aside, my advice (if you're in the position to do so), would be to forget the ALMA/ALMD instructions. They're bloated and very processor/communications intensive, and very inflexible. The last straw for me was having no way to get an "any alarm active" flag out of them, short of connecting it to a FTView SE system and using the alarm display object to write back to the PLC. That's way too convoluted for my liking, and what if I don't have FTView SE? What if I want to create repeatable code for applications with a PanelView Plus, or a Red Lion HMI, or even a panel with no HMI at all? Huge PITA.

I created my own AOI, called it ALM_D, and never looked back