Emcoturn 120 lathe retrofit

The 7I76E spindle enable and direction outputs are uncommitted OPTO outputs
so can replace a relay up to their current and voltage limits so normally no
relays are needed unless the drive cannot be programmed for ENA+DIR
vs FWD+REV mode

the drive has no enable. it only has fwd and rev that use the VFD logic ground. Can I use the 7i76e to switch the ground signal? Then I guess I dont need the enable signal at all?

LutzTD wrote: the drive has no enable. it only has fwd and rev that use the VFD logic ground. Can I use the 7i76e to switch the ground signal? Then I guess I dont need the enable signal at all?

Yes, I think you can probably just ignore the 7i76 enable output.
Do you need to be able to run the spindle backwards?

What does the VFD do if you activate (using wires) both FWD and REV inputs?

Since FOR and REV need to be grounded, one way to do this is to switch a SPDT relay with the DIR output,
connect the relay common to ENA+ ground ENA- and connect the relay NO and NC pins to FWD and REV

I think I might be tempted to wire ENA+ to FWD, ENA- to GND, DIR+ to REV and DIR- to GND, then see what happens.

It should work normally for Forwards spindle, and will either error in reverse, or just work. It depends on the internal VFD logic when both FWD and REV are true

pretty sure I saw in the manual if both a grounded it does not turn. I would need reverse for boring ops to keep the cutter on the same side of the tool holder and for tapping, so I would like to keep that option open. I dont mind having 1 or 2 relays, no issue either way, I have some on order so it will just effect my spare count.