I am trying to figure out how to do my wiring between a C10 BOB, to the C6 spindle speed control board, to the KBIC controller.

It looks like from the CNC4PC website, that the C6 to the KBIC controller is pretty straightforward, they show the following:

From C6:

Output GND to KBIC P1
Output 0-10V to KBIC P2
Relay1 Vcc in to KIBIC I2
Relay1 EN/CCW/NC to KBIC I1

Those are the only connections from the diagram they are showing, so relay 2 is not used.

I cannot seem to find anything on going from the C10 to the C6.

Has anyone wired a C10 or alike to a C6 to a KBIC who can help me out with this? The documentation I am finding is terrible.