Today was one of those days when circumstances stop you doing things

We seemed to have an endless stream of visitors all morning expecting teas and coffees - don't these people realise some of us just need to slink off to the workshop! Seriously though it it nice to have visitors.
Eventually I managed to get to the coal face and look at this turret issue. Turns out no way is the tool turret going to turn unless the safety cover is closed and locked. There are three digital inputs for 'door open' 'door closed' and 'door locked' and although the 'door open' one is toggling as the door moves, the others don't. What is supposed to happen is that a relay latches on for 'open', is released as the door closes, and another relay latches on for 'closed'. When the controller sees the 'closed' state it fires a solenoid bolt, and a feedback contact for this bolt generates the 'locked' status. The 'closed' relay is briefly clicking over but not latching on.
I strongly suspect that the latch circuitry was originally routed through the bar feeder, which I don't have, so I'll probably end up having to link it out. Not proved yet so something for tomorrow when I get back from taking four pigs on their last journey.
Investigation was greatly hampered by having all the relay logic at the back, and the safety sliding cover at the front, so you cannot see whats going on as you slide the door

Eventually solved this conundrum using the 'Indian Rope Trick' . I tied a length of rope to the door handle, and passed it right round the machine and back to the handle. Now I can slide the door from the back.

A low tech solution to a high tech problem.