IONI Pro feedback device

Can you please tell me if I can connect a single ended signal to IONI feedback pins? We have a weird feedback device with single ended SSI (essentially SPI). Or should I use RS-485 converter to make a true differential signal?

The reason I’m asking this is that I see some feedback pins for SSI (like GPI3, GPI2) can also accept single ended signals. But I’m not so sure about C- and C+ signals.

Also there is some conflicting specification on Wiki.
1.This schematic shows a 3.3V ESD protection on IO pins:

Although SSI communication is specified as RS422/RS485 which is ±5V or more!

  1. For SSI encoder it is specified that I should use pins 11, 12, 14, 15 on X2 connector. Here it shows they are all inputs(green):

But Clock pins should be output? How does that work?