7i76e encoder channel?

I re-purposed a 7i76e for a CNC mill conversion, previously it was used in a more specialized build. On the other build I used an NPN proximity switch with the output connected to ENCA- and that worked fine. I used NPN because most proximity switches use a minimum voltage that is higher than the encoder inputs 5v tolerance. The NPN just sinks the input to common.

I was trying to connect an optical break sensor which is PNP and I expected to just connect the output to ENCA+. I noticed all the ENC+/- inputs are at 5v to common with nothing connected. and HALshow shows the encoders true. The jumpers were all originally set to the right, I don't recall it specifically being explained what each jumper does, but the manual suggests swapping them for "TTL input". Moving the jumpers left has HALshow see the inputs as false, yet they are all still at 5v to ground. I would expect 1 side of each input to be sunk so I can pull it high with a PNP sensor. Is something wrong with my board or am I looking at this wrong?

The jumpers select differential or TTL (single ended) input mode
All inputs have pullups to 5V so will not work with PNP sensors

In addition the inputs will be damaged by input voltage greater than about 13V
so you definitely do not want to connect 24V PNP proximity sensors to
any high speed encoder input.

NPN proximity sensors will work directly with the encoder inputs

You can make PNP sensors work if:

1. They are 5V powered
2. You add a stiff pulldown from the encoder input to ground (say 200 Ohm)

I knew they couldn't handle anything above 5v (this was a 5v interrupt "fork" sensor). I didn't realize both the + and - sides of the input were supposed to be pulled down, I usually use switches for speed rather than actual encoders but now that I think of it I guess they usually are NPN.

I can easily just use a sinking switch, thanks

You don't need to pull down both sides when jumpered for single ended, only the + input
( the - input is not used in the single ended case )

Yeah I originally had the jumpers moved to the right and the output of the NPN prox was hooked up to the enca-. I don't think I understood how the encoder setup worked at the time and "-"seemed more intuitive, but this setup worked. I just have to find an NPN fork sensor and I should be good for now.