I managed used a fleet with all sizes 2yds up to 25 yards)
They are simple machines. No diagnostic controllers. As stated the electric is just o Or off. Hydraulic have spinner and chain adjustment.
We had older ones since new they are 20 years old now. Motors are easy to replace, chains are easy to grease. They are nice and simple.
Nope just a fuse on the power line to the switch. They are pretty durable and idiot proof. The only week spot is the greasable bearings. If you don't grease them they fail and you have a bad day. A couple pumps a day keeps the mechanics away.