Category: General LinuxCNC Questions
Those pins need to be open collector pins according to the docs.
As you have followed the correct procedure to test if the pins are open collector and you saw no change that indicates that those pins are not open collector and can not be used as inputs.
As far as I know, I haven't looked at any data sheets, there is no way this can be changed.
I'm guessing this is the way the hardware is implemented on the chip itself, IE at the silicon die level.
The only way to find if this can be changed is to read the data sheets of the chip used on the board. Even if it may be possible it may require some mods at the PCB level.
Bear in mind that as I have not read the data sheets most of the above is speculation.
