RedKingRory
Member
Hello everyone,
My colleague and I have encountered an odd situation. We noted that, according to the historian trends, the bits in a particular rung were all such that the rung condition was true at a particular time, yet the OTE on that rung did not appear to execute (go true). This was on a PLC5/20 Enhanced.
Obviously this is a troubling thought, since the entire PLC control scheme relies on proper functioning of the rung conditions.
Has anybody ever encountered such a situation? Is there anything which might cause reliability of the output table being written to in these PLC's?
Any thoughts would be most appreciated.
My colleague and I have encountered an odd situation. We noted that, according to the historian trends, the bits in a particular rung were all such that the rung condition was true at a particular time, yet the OTE on that rung did not appear to execute (go true). This was on a PLC5/20 Enhanced.
Obviously this is a troubling thought, since the entire PLC control scheme relies on proper functioning of the rung conditions.
Has anybody ever encountered such a situation? Is there anything which might cause reliability of the output table being written to in these PLC's?
Any thoughts would be most appreciated.