Thank-you [email protected] for you continued support.

Let me explain some more of my issue.

I tested 3 states on the relay.

State #1: All wires disconnected from the Relay (NO POWER) and got the results noted in Test #1. All was as expected and consistent with your guidance.

State #2 All wires connected to the Relay, AXBB-E, VFD and PSU energized, but no M3 call from UCCNC. This is the one that gave me the unexpected results in Test #2. I expected State #1 and State #2 performance of the relay to be the same. The relay should only be energized when there is a M3 call.

State#3 All wires connected to the Relay, AXBB-E, VFD and PSU energized, plus M3 call from UCCNC. This gave me the results noted in Test #3. Again this was as expected and consistent with your guidance.

My ATC has 3 pneumatic valves which operate as follows (the manual is unclear so I've deduced this operation with much testing):

MODE #1 LOCK: This mode is activated while the momentary push button is in normal position (i.e. not pushed). This mode injects air to keep the Spindle locked. I connect the solenoid as NC (on loss of DC power this valve will continue to keep the spindle locked). This is why when the CNC is powered off the collet does not drop from the machine. Even if I disconnect air pressure the collet will not drop from the machine because you need to activate the REL mode to disengage the clamp spring. The clamp spring alone will prevent the collet from dropping.

MODE #2 REL and DUST: This mode is activated while the momentary push button is momentarily pushed in. This mode will cut DC Power to the Lock solenoid and is the first step to unlocking the Spindle. Subsequently air is injected in the spindle that disengage the spring clamp plus pushes the holder out of the spindle. At the same time there is another air feed that clears any dust from the spindle. The REL and DUST valves operate together in a NO fashion. On loss of DC Power they are not active.

Now I don't want MODE #2 activated by accident while the Spindle is spinning (M3 command) so I connected to the second set of poles on the relay as noted in the updated wiring diagram. I am using the second set of poles to open and close the 24V circuit to the solenoid valve. I want the 24V circuit to the REL and DUST solenoids open when there is a M3 call so that pushing the momentary switch will have no effect.

Here is the confusing part. The spindle "on" - "off" through UCCNC works. My original request for assistance is resolved.


The second set of poles is not working. The ATC works properly if the solenoid valves are wired to bypass the relay. When I wire as noted REL and DUST valves continue to operate regardless whether there is a M3 call or not. To test the M3 used MDI command M3S0 (activate the spindle but run the spindle at 0 RPM). Maybe this is not appropriate?

JohnVFD_UCCNC_AXBBEwithRelayandPushButton.pdf