HURCO KMB-1 Control Update

The video

Caught up on my education last night. skunkworks video is a revelation.
Understanding how to use the halcmd, and halmeter to choose correct hal syntax and then use halmeter to confirm what you've written works was just fantastic.
So much so, that I think my estop circuit problem may be a 7i77D versus 7i77 issue.
Mine is supposedly a 7i77D, but when an output terminal is true, it outputs 24volts, where I was expecting it to sink.

Turns out its a 7i77 with a 7i77D (d for digital)  quality sticker  on the underside rather than a 7i77D type.which has that written in the artwork on the topside.

ULN2003AN array has been my solution until the 7i77U become available.

The 5v limits switches, (connected to the 7i77 spare encoder terminals QA3,QB3,IDX3 etc), are registering in linuxcnc randomly. Even though the machine is parked mid stroke, the Y axis min is always true, and I can trigger the X max with a wrench from false to true, but it stays that way with the wrench removed.
Looking at the original control there is a 470ohm resistor to 5v holding the signal to the MUX chip high, and when the limit is triggered, this gets grounded.
Do I need to do something else electrically to gets this working?
Thanks

Are the encoder inputs for the limit switches jumpered for single ended use?

Aha, no they weren't.
But they are now.
Can now toggle them all to change state, but oddly y-min is inverted, and cannot quite see what I have done wrong there.

Thanks again.

Actually the A/B inputs are inverted (which is what you want for an active low home switch input)
But the index input is not inverted.

options:

1. If you have more spare encoder inputs, just use A,B

2. Add 1 or  more  "not" components to invert the polarity of the input-index pin