help with a fault on SLC-5/03
Posted 24 May 2005 - 08:41 PM
real training, so go easy on me.
Ok, here is my problem. I got 5 AB SLC 5/03 systems running that are networked together by DH-485 link couplers. 4 of them are robotic cells the other is a parts conveyor. All of a sudden one of the robot PLCs will fault and shut down. It only happens when its time for it to unload into the parts conveyor, before then everything is fine. We had this problem once befor and the SLC 5/03 CPU was swapped out and it worked again, well I tried that this time and still the same thing happens. Does anybody have any suggestions? Thanks
Posted 24 May 2005 - 10:25 PM
Posted 24 May 2005 - 10:28 PM
Major Error Halt S:1/13= 1
Math Overflow Trap S:5/0= 1
A minor error bit is set at the end of the scan. Refer to S:5 minor error bits.
Posted 24 May 2005 - 10:42 PM
Posted 25 May 2005 - 05:33 AM
Posted 25 May 2005 - 10:37 AM
in addition to the excellent advice already posted, you might want to take a look at the “Basics of Math Overflow Faults" in this post ...
and possibly the handy trick to help track down the offending “bad math” rung covered in this post will prove useful ...
hope that this helps ... and welcome to the forum ...
PS ... I have no idea why your original thread is marked "closed" ... but I decided to post this information here (in a new thread with the same title) just in case you might find it helpful ...
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Posted 25 May 2005 - 01:52 PM
Posted 25 May 2005 - 02:30 PM
Ron, Thanks for straightening me out...I scanned your links, but apparently didn't read them very well. It seems I can remember using the S:20 and S:21 words to troubleshoot math overflow problems in the past, but perhaps I was working on a different type of fault.
Thanks, and sorry for any confusion I might have caused.
Posted 25 May 2005 - 02:33 PM
Posted 25 May 2005 - 04:40 PM
Thanks again for all the help.
Posted 26 May 2005 - 01:10 AM
Posted 26 May 2005 - 07:47 AM
Even with the limit tests looking for underflow and overflow conditions I've had that bit set and the suggested fix came from a local AB tech. I traced one instance down to a CPT instruction that was computing an answer for display purposes but that was as far as I could go. No way was I going to spend a lot of time on something that could be firmware related so I put the patch in and moved on.
I wouldnt add that code, unlatching the overflow bit, Personally, i think thats a chickenshit way of doing it. All you need to do is properly condition your math, and the problem is solved. I see lots and lots of engineering companies unlatching the overflow bit, when all it takes is a properly written program to solve it
Posted 26 May 2005 - 09:24 AM
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