Newbie- Driver board is not equipped with free pin outputs!

[TheProCreator]

I am trying to set up my blue-screen z touch plate probe. The problem I am having is that I can not figure a way to wire it up with my driver board. the instructions that I have list the pin configs as follows:


1 all-axis enable
2 STEPX
3 DIRX
4 STEPY
5 DIRY
6 STEPZ
7 DIRZ
8 STEPA
9 DIRA
10 LIMIT-1
11 LIMIT-2
12 LIMIT-3
13 LIMIT-4
14 relay control
15 vacant
16 STEPB-pass extension interface DB9 pin 8
17 DIRB-pass extension interface DB9 pin 7
18-25 GND


I am not using the on-board relay for the spindle as of yet and pin 15 would be ideal, however I only have screw terminals for XYZ limits and Estop.

I tried to double up on the Z limit pin but this did not work.

The terminals in the upper right have a +5v and a ground, but these terminals or the three slots between are not wired to any pin I/O that I can see.

Any suggestions?