I am running a pokeys57cnc and mach3 on windows10 with the A-axis slaved to the Y-axis with both Y and A having their own drivers, motors, and limit switches to enable auto-squaring. Everything worked as it should when I used the keyboard to control it, but  when I used a pendant in continuous jog mode, the Y-axis moves in both directions as it should, but the A-axis only moved in one direction racking the gantry. When mach3 is in step mode, everything moves in the  right directions using the pendant. I first was trying to use an x-box  controller, and it had this problem. I thought it had something to do with the x-box plugin, so I bought an iMach3 P4-S Pendant. It had the same problem. I removed and re-installed mach3 and went through all the  settings, and the problem persisted.  I asked VistaCNC if they knew of a solution.  They wrote a modified plugin that corrected the problem.  Now I have a fully functional system thanks to their support.  The benefit to all this is not just that I can use a pendant with my system, but the pendant is really awesome.  The P4-S pendant gives precise control of the machine much better than the keyboard.  If you run this configuration, you will have this problem.  The imach pendant is incredible, and vistacnc supports their product which is really rare these days.