Reusing PGC & PGD pins

[richard]

if your re has the possibility that it can be stationary with either A B contact closed [ground] then it will always be possible to stuff up programming and no isolation other than disconnection will work

the isolation objective is
1 don't impose a logic level on the pgm pins that will damage the programmer
2 don't impose a load on the pgm pins that will corrupt the programming signals
3 allow your signal to reach the pins without signal corruption

[Demon]

if your re has the possibility that it can be stationary with either A B contact closed [ground] then it will always be possible to stuff up programming and no isolation other than disconnection will work...

Yup. I've reached the same conclusion.

I have to use a jumper.

It would have been nice to figure out a "built-in" solution, but that's not happening.

[Ioannis]

Most encoders of good quality should have the contacts open. At least I have not encountered any that was not.

But in case a contact on RB7,RB6 is closed I would definitely use a jumper. Not resistors.

Ioannis