FTView ME Alarm Setup

[FactoryTalktotheHand]

I'd just like to confirm this works, if I could.

In my project, I have 4 Alarm DINTs that I'm using for triggers at the bit level. If I set up those 4 DINTs in the alarm trigger setup, and set the trigger type to Bit, then....

When I set up the Alarm messages, do I assign the particular DINT to the Trigger field and the individual bit to the Trigger value?

So for instance, if I have AlarmWord[0] in the Trigger field and 3 in the Trigger value field, will that message appear when AlarmWord[0].3 is true?

 

[benaiahhenry]

When I set up the Alarm messages, do I assign the particular DINT to the Trigger field and the individual bit to the Trigger value?

So for instance, if I have AlarmWord[0] in the Trigger field and 3 in the Trigger value field, will that message appear when AlarmWord[0].3 is true?

Almost, I believe that the "Trigger Value" is 1 based not 0 based so to get the message associated with AlarmWord[0].3 you would use trigger value "4"

-Benaiah

 

[Operaghost]

......When I set up the Alarm messages, do I assign the particular DINT to the Trigger field and the individual bit to the Trigger value?

So for instance, if I have AlarmWord[0] in the Trigger field and 3 in the Trigger value field, will that message appear when AlarmWord[0].3 is true?

As benaiahhenry mentioned, the acceptable bit # in the trigger field is actually 1-32 instead of 0-31. A zero is not a valid trigger value unfortunately. So his example correctly points to bit #4. Since he said "I believe" I wanted to confirm.

OG

 

[Paullys50]

http://www.plctalk.net/qanda/showthread.php?t=42339

 

[FactoryTalktotheHand]

Almost, I believe that the "Trigger Value" is 1 based not 0 based so to get the message associated with AlarmWord[0].3 you would use trigger value "4"

-Benaiah

Ok. Thanks! I'm kind of scratching my head at that one. I wonder why Rockwell would use 0 base absolutely everywhere else but when it comes to alarm setup they start with 1. Their inconsistency is a bit frustrating.

 

[Paullys50]

Ok. Thanks! I'm kind of scratching my head at that one. I wonder why Rockwell would use 0 base absolutely everywhere else but when it comes to alarm setup they start with 1. Their inconsistency is a bit frustrating.

From the thread I linked earlier:

3. In the Messages tab:

"Trigger" is ALWAYS {[PLC]AlarmBit[0],L10} for every alarm!

"Trigger Value" is the returned BIT POSITION of the bit within the array that is true. Bit Position starts at 1 NOT 0. Specifying "Bit" back in step two for the trigger type tells ME to return the bit position.

So if AlarmBit[0].0 were true, ME would return a "1". The Alarm Message that has a "Trigger Value" of 1 would appear.

If AlarmBit[9].31 were true, ME would return a value of "320" and the message for the trigger value of 320 will appear.

I put that together years ago, but it's in the help files if you dig into it. A hassle yes, but having to deal with n+1 offsets isn't unheard of in computing. And as you can see in this example, if you your multiple arrays, you still need to convert [9].31 to some "value" for the alarm to be triggered. So as soon as you overflow into the next array element you need a different value anyway. .0-.31 makes sense on the surface as 0-31, but what happens when you need a value at bit 0 of the next array? That is now back to .0, so does 32 makes sense? 33? In my example I show how you can use a single trigger value across multipe elements in an array, in my opinon the +1 offset is a trade off to have a single trigger for every alarm.

 

[FactoryTalktotheHand]

From the thread I linked earlier:



I put that together years ago, but it's in the help files if you dig into it. A hassle yes, but having to deal with n+1 offsets isn't unheard of in computing. And as you can see in this example, if you your multiple arrays, you still need to convert [9].31 to some "value" for the alarm to be triggered. So as soon as you overflow into the next array element you need a different value anyway. .0-.31 makes sense on the surface as 0-31, but what happens when you need a value at bit 0 of the next array? That is now back to .0, so does 32 makes sense? 33? In my example I show how you can use a single trigger value across multipe elements in an array, in my opinon the +1 offset is a trade off to have a single trigger for every alarm.

Oh I agree. Even with the slight inconvenience it's well worth it. Much easier than having to manually create every individual trigger.