SLC 50/4 minor error bit

Newby here, I'd like to pipe in on this old thread as well and also want to say thanks for the valuable information. We had similar issues and ended up replacing one of the boards/cards to correct this issue. I wonder if we could have made the changes to the program as mentioned in this thread. BTW - this system was running without issue for 14 years.
 
I have seen the math overflow fault set with everything normal some math functions will cause the fault. I ran into it many years ago call tech support . recommendation was to on the last runs of the code clear the math overflow bit if its set when the ladder code rolls over to rung o you get the fault. it doesn't happen every scan it depends on the result of a math function calculation.
 
Thanks

Thank you guys for posting valuable solutions long ago, I just had downtime on some new systems I recently installed, I'll apply your teachings, just to let you know there still helpful.

I got a Micrologix 1100, Tension Control System: encoder counts, speed average, PIDs, regression speed formula, offsets, Acel and decel; so lots of math.
 
If you get a math overflow bit, there's a very good chance that you're putting a number outside of integer range into an integer, as the result of a move, cpt, etc.

While the processor is still faulted, look at the values of ALL integers usng the data monitor. Go to the rungs of the integers that are maxed out, or +/- 32767. You'll probably find the culprit that way. Look at the analog I/O values too.



thank you, :) you saved me we are grateful :v
 

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