Quote Originally Posted by Kenny Duval View Post
Correct. If the ESS is being commanded by Mach 4 the output is either active high or active low. Motor on is likely active high so you should see 5 volts from the pin on the ESS assigned to close the relay. The other portion of that control would be direction. Forward or Reverse would also be assigned a pin and an active high or low output from Mach. That is assuming you aren't talking directly to the VFD via RS-485.
Kenny,

For the Hitachi drive on our machine, FWD and REV and wired to the intelligent relay board of the drive and their functions are assignable. When we tell Mach to run the spindle forward, through the ESS, it closes pin #1 on port #3...the screen shows it doing that.

That output from the ESS (pin#1) powers a relay on the 3660 BOB which is wired to the VFD. That closure on the BOB commands a FWD command to the drive and the spindle starts.

The same things happens for a REV command but using a different ESS pin. For REV, ESS pin #17 closes which powers a different relay on the BOB which in turn tells the VFD to run REV.

If I pull both output wires from the 3660 relay board off of the buss of the drive and stick a meter on them, whenever a FWD or REV command is sent from the ESS to the BOB, both those output wires become energized. The ESS screen readout indicates only one is firing..not two. When both wire fire, the VFD see's a FWD and REV command at the same time and will not run.

It's a brand new MX3660, all spindle speed commands to the drive work fine as well as all motion control for the steppers..only the spindle direction is goofy. All the diagnostic stuff on the screen for the ESS looks perfect and it's sending all the proper stuff to the stepper driver as spindle control and motion control work perfectly...only spindle direction commands are goofy.

My gut instinct tells me the MX3660 has some type of glitch in it.

If you can verify the ESS is only powering the commanded relay pin and not two relay pins then it proves the ESS is not at fault for the glitch. I just am not sure how to do that without releasing any magic smoke from a apparently functioning ESS board.

Does this make any sense at all?

Stuart