Also of interest and for reference, I eliminated the solid state relay, as I occasionally got “probe is already tripped” errors and was thinking that removing that extra component might help narrow things down. I am still working out what I may be pushing the limits on in terms of probing or minor configuration issues, as I still occasionally get them during routines that have many probe moves in rapid succession.
You MUST independently verify with a multimeter your specific machine control input circuitry but on the GP-800 probe, which does not have a contact closure output, I am able to use GND and +24VDC to power the receiver. On my revision of GP-800, the default dip switch for the output green wire is setup such that the green output wire “skip“ is effectively read as NC when connected to the control input pin that is pulled up to 24VDC on what is normally a contact closure input that expects to be closed to the other pin (which reads as ground).