This is an odd one, and I'm curious to see if anyone else has encountered it.
I have three Quantec KR240s running on KRC4s (with KSS version 8.2.22), to which I have had to add one external axis. This external axis is locked in Asynchronous mode, using $EX_AX_ASYNC = 1, in order to control the axis from the SPS using ASYPTP commands.
Everything works, except one thing: when I try to Master E1 using the EMD, when I hit the Step Go button, the brakes on the robot and the E1 motor click open for about 1sec, then close again. E1 never moves. There are no messages on the SmartPad, error or otherwise. This is 100% consistent across all three robots.
However, if I turn off the Async setting temporarily (under CONFIG>EXTERNAL AXES), I can master E1 with the EMD perfectly well. So currently, I switch off the Async option for E1, EMD-Master it, then turn the Async option back on.
Even after getting it to work once, any attempt to EMD-master E1 when $EX_AX_ASYNC is set gives the same failure.
One thing I haven't had a chance to experiment with is if $ASYNC_AXIS has a similar effect.
Has anyone else run into anything like this?