have a very intermittent 56 fault, it will run a week, then fault 3 times within a couple minutes and shut down. it will run a couple days and do same thing, never seen it happen, replaced various relays, dsp board, it has a dsd312 drive, and it has no stored faults, so don't think it is an actual drive fault. also using fltn command, the last time it happened, it was floor level, with velocity at 0 it faulted on a 56 2 times within a minute or so, then it took off for a long run, 19 floors, it almost made it to the top, and logged a 56 at 451 fpm. this one is killing me, been going on for a month now. any ideas? also been thru m contractor and auxiliary contacts