text: <s>[INST] MAM instruction 'stuck'??? Had a weird one at a customer site yesterday (about 4000 miles away from where I'm sitting unfortunately). Machine hasControlLogix, lots of servos & motion control. One particular axis would not move from one particular MAM instruction. Other MAM instructions on the same axis worked fine. The one which wasn't working had it's EN output set and all other outputs clear. Toggling the rung-in condition made no difference to the instruction or its outputs, it just wouldn't do anything. Other MAM instructions in the same routine operating on the same axis with exactly the same parameters worked fine. In desperation I got them to upload/download and it was then OK. Anyone had anything like this happen? It smells like a ControlLogix bug. Mike [/INST] Digging back in time I see that I've come across this before (different machine - one I was programming unlike the one I was trying to support yesterday). I actually raised it as a case with Rockwell and got this answer: Before you execute a MAM instruction, put an interlocking tag in there indicating the Axis_Servo_Drive.ServoActionStatus Boolean is a 1. Are you sure no other instruction may not be completed before the MAM is executed in the program? The instructions 'hang up' like this sometimes because during the scan when the rung is true, the axis cannot complete the instruction to be true. In otherwords, the .EN will stay true until the process of enabling the instruction is complete and the rung goes false. Thank goodness I keep my emails! Mike \\n </s>