Finding A Home

In all these checks on the A axis I was wondering why the diagnostic page shows an A axis home output but there is no A home in the 14 pin ('91 machine) cable. The XYZ homes go through a separate connector from the servos and the A axis 14 pin connector is full with the encoder, motor, temperature and brake wires. When I traced the receiver board (between the machine connector and Motor Interface board) there was one pin unused on the input side, P4.6, that goes directly to the output connector, P8.6. This pin goes to the Motor Interface board P9.6. Following that trace it goes to P24, the Homes connector. The XYZ connectors also have this pin (P#.6) going to the Homes connector, which is wired to the external Homes connector on the chassis.
So if you want to use A home you have to wire into one of these pins and turn Off the Z Channel only parameter on the A axis.
If you are custom wiring a rotary you might be able to use the M pin of the A axis chassis connector. The brake (cable 390) uses pins G&M but ground is already there through the N pin.