Ensure input X56 is on when dryer is at home.
Check the contacts on the plc, some times the Dryer PLC contacts stick, I some times recommend putting a single pole relay in the circut so the plc output doesnt power the magnets directly. This reduces the current load on the contact in the plc.
Check the ohms of each magnet, should be about 12 ohms.
Ensure that inputX56 is mirroring output Y 47, this will be a good indicator of your comms to the dryer.
Any questions give me a call
Regards
Mike