2m542 source or sink current help?

[Evengravy]

I have some issues with wiring on my cnc and was wondering if some more experienced guys could step in. I have searched around and found a thread with similar issues but I still have a bit of a hard time wrapping my head around current source vs sink arrangement:linuxcnc.org/hardy/lucid/index.php/engli...tle-assistance/reply


I have my cnc wired with similar hardware, ZP5A-int breakout board with 2m542 drivers. I have been running mach3 but missed steps occur often.


Initially I set up my breakout to source current to the drivers as in the second image attachment and things seemed fine at first but missed steps are common so I now believe that my BOB can't source enough current to drive the driver optoisolator inputs on my 2m542 drivers correctly so want to move to current sink ( image 1) as per this thread (although i'm having difficulty wrapping my head around this arrangement)

If anyone can shed some light I'd appreciate it.

thanks and regards