Fanuc OMc M-Code and Indexer

[charger19690]

So I have been reading a bit and wondering if I can get a little detailed answer.

I have an 1990 Kia KV40A with a Fanuc OMc control bought at auction.

I bought an old Haas Indexer with a Control Box. Pretty confident that I can wire it up to the control box reading the Haas Literature, but my problem lies with finding an M code.

My buddy in his shop has 4 of these machines, 3 which were wired for signal driven indexers which use I believe M71 as an index code.

I paged through my "Ladder" (which I don't completely understand) looking for an M71 code. No luck. I found everything from M1 to M90 and M91 (Door open and close). At the control when I type in an M71 in MDI, the cycle start light comes on and waits.

My questions is, could these mean this is a valid M-code on this control and is waiting for the MFin relay to fire?

Overall, I am wondering how to track down this particular code, or page through the Ladder and look for something different? Or should I just through caution to the wind and use find the Door Open relay M-Code that isn't being used. (By the way, this machine is a semi-open faced machine and has no automatic doors. It also has Pallet clamp and Unclamp M-Codes in the ladder???

I was thinking about just hitting the M71 in MDI and tracking down the MFin relay and see what happens, but I figured I would see if there was any direction here first.

Mike in MN