The bug was experienced on an XL200-MRE2 with a linear DA configured for the Shear. The Run output would stick on if a Tail-Out occurred during the acceleration before the Shear Press turned ON. Tolerance Mode was set to Cut and Stop.

New code was added in SCN 4435 (released in V4.72.00) to handshake the shear operation with a PLC. It was preventing the Shear Press cycle from starting if the Run Mode was Halted. The code entered a loop that requires the press cycle to be active and to complete in order to exit. The press cycle was requested and assumed to have started but this new feature mistakenly prevented it and then the shear task was stuck in the loop with no way out. Since it was stuck, the Run Task was waiting forever for it to finish up and that is why the Run output remained on.

As a safety measure, code was added to this loop to give it a way out if the press is not active and the Run Mode halts. It should never happen but it is there just in case some other bug, present or future, creates the same condition.

The actual bug in the code exists in the Open Loop as well. It is unknown what its symptoms might be if encountered.