Put a voltmeter on the Dir pin and do your jogging and note whether its 5v or 0v then when it does its strange reversal thing have a look at the voltmeter and see if its swapped. Obviously this will have to be on the parallel cable side of your breakout board as you are wanting to check the signal direct from Mach, not sure how easy it will be to get that pin, will depend on the makeup of the board.
Hood

That should be very easy to do

My BOB has output connectors which I can wire as needed (presently nothing is connected there)

My direction pins are 3, 5 and 7. I will connect the voltmeter tomorrow and post back the results
Nicolas

You want the computer side of the BOB, not the drive side as you want to make sure the signal from Mach is the one thats getting reversed and not in the BOB.
 Suppose I should have asked if the DROs in Mach are showing the unwanted reversal.
Hood

You want the computer side of the BOB, not the drive side as you want to make sure the signal from Mach is the one thats getting reversed and not in the BOB.
 Suppose I should have asked if the DROs in Mach are showing the unwanted reversal.
Hood

Yes I understand, the outputs I mentioned are taken from the printer port. If you want to have a look at my BOB, here is the link.
http://www.probotix.com/manuals/PBX-RF_manual.pdf

I never noticed the DRO's if are moving when the axis is reversed. I will pay attention tomorrow and post back
Nicolas

You would have to connect to the port where I have circled in red to be sure as the connectors at the bottom have passed through the isolation. But knowing whether the DROs show the reversal will tell you as much anyway so easier to look there.
Hood

It will be difficult to connect there but I will give it a try and post back
Nicolas

As said above watching the DROs will tell you a lot so I would do that first.
Hood

As said above watching the DROs will tell you a lot so I would do that first.
Hood

Yes the DRO's are moving in both the X & Y axis but the number is always positive regardless of the direction (has always the plus sign infront)

Does this mean something?
Nicolas

Yes but when the axis starts reversing when it shouldnt are the numbers still counting the same way or do they start going the oppopsite? If same way  then the problem is not Mach or keyboard but could be anything from Port out. So next step would be to put the volt meter on the Dir signals and see where its happening. If where I mentioned earlier is too difficult then try on the output blocks and see but if it  does reverse there then you will have no option but to test on the port.

Hood

Actually just reading your post again, are you saying if you jog to zero and keep going then it doesnt show negative but starts counting up still positive?

Hood

ok I zero the X & Y and start to jog. The DRO's change according to the keyboard, pressing UP arrow numbers are positive and pressing DN arrow numbers are negative. But the axis is not following the keys I press. Like I keep pressing the UP and the axis will go one direction and when I release / press the same key again it changes direction. In other words the keyboard arrows works fine along with the DRO's but the axis goes like crazy in either directions, not consistent.

The manufacturer of the BOB said that I can take the readings from the outputs but I cant do that alone like holding the probes and joging the motors. Waiting for a friend to give me a hand
Nicolas