Testing XYZ axis, and weird result (of course !)

I have set up my three axis with the limit switches disabled to check the motor stepping.

The whole system has been sitting waiting 6 months for me to get back in the workshop and finish the new setup, and sorting out the limits was the next job.
In a previous life with other cnc software, the m/c worked, but I wanted to move from 2.5D to 3D.
The controller is EMC-XYYZB, based on L297s, built to run SuperCam software.
Three identical motors, XYZ, and the mechanicals are all similar. The Y2 output socket has a jumper, as per the manufacter's instructions, as I'm not using the original design with two motors on the Y axis.

With the motors connected to the controller, X and Z jog, Y doesn't, but is being "locked" by the current through the windings.
I removed the connectors and plugged Y motor into X controller socket, and it jogged OK.
So I plugged the X motor into the Y socket, and guess what, that jogged.
Switched back, and the first condition reappeared.
Plugged the Y motor into Z and that jogged, but the Z motor into the Y socket didn't.
X and Z motors both jog in each others sockets.

So Y and Z motors don't jog, but will lock up, in the Y socket, but all other combinations jog.

I've checked the Stepconf settings, and all are identical with the exception of the steps/mm of the Z axis.

Ideas anyone, as my logic can't spot the error that I'm overlooking ?

John

I've narrowed the problem down, but not there yet.
If the Y cable was slowly pushed into it's socket while the test "Run" was operating, the motor started to turn. Pushing right home killed the motor.
This led me to suspect that something was amiss inside the controller that only affected the Y socket, even though the X motor worked when using that socket.
For no reason at all, I pressed the Y limit switch, even though these pins( 11,12 and13)had been set to "Unused" in the stepconfig, and the Y motor then started to operate normally.

So, it seems that the limit switches on the Y axis haven't been disabled, but the ones on the X an Z have been (I checked them, and they have no effect as expected).

I've gone back to the paraport pin set up, and played with the settings of pins 14,16 and 17, and notice that setting them to either Amplifier or Unused has different effects on the 3 axis.
I can't spot the pattern yet, but this the area where I suspect I'm getting the problem.
I think I've got something not set right, and will have to go back to my cct diagrams and compare them with the suggested settings in EMC.

John
EDIT: The statement, "even thouth the X motor worked .." above, is wrong. I discovered that the NC limit switch on that axis was not connected, so the result is the same for the X and Y motors if they are connected to the Y socket on the controller unit.

I've just re-read earlier posts I made on the cnczone, re this controller, and think I may have the answer.
The Y axis, designed to have a two motor option, needs N/O limit switches.
At least that's my interpretation, and certainly that's the condition in which the motor moves.
So it looks like a swap round for that axis limit switches, though I would be happier with the fail safe that N/C give.

Any ideas how I can get fail safe with needing a low (?) on the input pin ?
Perhaps I'm just being over cautious ?

John

Some progress.
With my controller, which is designed to run one or two Y axis motors, the part of the cct that splits the single Y step into two requires an inverted enable signal on pin 1 of the paraport.
So three N/C still seem to be in order.
All three axis now operate identically, i.e. they all ignore the limit switch settings during the "Test this axis"