I had this happen again. Unfortunately, they needed the machine to run and I couldn't debug it. However, I did reboot the device that it was talking to and no change. I tried putting a long watchdog timer on the rung and restart the instruction but no effect. No faults nothing. It just doesn't move on until I do a Pgm/Run transition. I did put the new firmware in. It is just so infrequent. It has been months since it happened last and the machine ships to Mexico next week. Have you seen anything like this? Why doesn't it reset when I break the input line? Sorry I didn't check the device status, it has been so long I forgot to look for it.