FANUC 0M. ADDING I/O TO NOT USED RELAYS

Hello everybody,

We are doing some improvements to our machining centers (automatic clamp system by code, piece count in big screen, buzzers, ...). We are going to begin with two machines with FANUC 0m controls that have several unwired relays.

In the schematics, we've realized that relays (Y outputs) should be activated by some M codes after a input confirmation (X inputs) but, when we execute them in a program, program stops waiting for X confirmation, put the input in high and program continues without changing the relay status.

Program example:

O200 (Relay test)

M68 (should activate an output relay named 49.1);
(Program stops)
(After waiting some seconds, we activate the input X associated to the output X19.1)
(Program continues without any change in relay)

M10
(Same stuff happens, no relay changes)
...
M30;

Thanks in advance for your help. Maybe another posts with this problem but I cannot find them.

All Y addresses are physical (real world wires and components) outputs from the control, possibly turned on by M codes. Though they are not preceded by X inputs. (Also real world devices) Actually the opposite is true. An X input will typically supply the control with a signal that verifies that the action the Y address (M code signal) asked for has actually happened. A FIN or finish signal as it were. In short, an X answers a Y. Not the other way around. Although an X answering a Y command may allow another Y command to commence. This would be in the ladder which is something not easy to change.

Sometimes machine tool builders supply M code pairs, (M10/M11) Or maybe (M40/M41) (example only) to give you the opportunity to do what you're trying to do. Some of them my or may not need a finish signal to work. Example: once I wired an air solenoid to a relay to give me M7 air blast at the spindle. M9 turned it off. The whole thing operated without verification. (No X involved) These are the simplest types of I/O to connect. Also there is no danger involved with turning on a air blast, so operating without verification is not a problem. Other things like your fixture clamping will need verification to be safe. These will need some X input. Hopefully the machine builder has supplied the wiring for it.

This can all be a lot more involved then I'm getting to here. It's too late in the day to bother with more now.

Hope some of this helps.

Dear Gentlegiant,

Thanks for your help and your time. We usually construct our dedicated systems and use control and actuator as the ones you've told.

The problem that we have is that, even some outputs relay are show in the electrical schematics (but not wired), these relays do not physically change of state.

Also, when we execute a program with these Mcodes (that may control these relays)
- the relays do not changes of state
- the but associated to the Y outputs in the diagnosis parameter screen don't also change

That's the real problem that we have.

Anyway, thank you very much for your time.

Hello Juan,

Okay I think I understand what you're talking about. You probably won't get a change of state because you have yet to complete a full circuit. Depending on if you have a sinking (grounding) or sourcing (+24V) control, you still need a complete circuit for the state to change. If you're outputting lets say a sourcing +24V Y address, until it sees ground it won't change state. Meaning if the wiring isn't complete there is no complete circuit. You might try taking a digital volt meter and connecting it to the pin of whatever Y address output you're expecting to turn on. Maybe there you could see the 24 volts go on and off, but I don't think the bit will change without the 24v output seeing ground. I'm not 100% on this but am pretty darn sure.

FYI - On that M7 thing I talked about earlier, where I set up an air solenoid to give me an air blast at the spindle, I had to physically add a connection pin and wire to one pin of the 50 pin Honda Connector on the relay board side of the connector, and connect that wire to the relay coil on the back of the solenoid panel. The wiring form the control was already there on the control side, but no pin was present on the relay board side. You might be suffering the same problems. Sounds like you have all the wiring books. Look at you connector pin-out sheets and physically verify that the wiring is there on both sides of any connector.

If you do hook up things, don't forget the snubbers across all relay coils. You don't want to fry any sensitive control circuits. Just use the same type and style that is already in the machine on other devices.

My machine is a 97 YCI Supermax 3 with Fanuc OMC control.

Hello Mr,

Thanks, tomorrow we will check it.

We have already checked in the relays 24V, 0V, AC, DC grounding, sourcing, blaming, or saying beautiful things to the control with no result. Wiring between control board and relays block exists with a multipin wire but I will physically check it.

As you've told me, tomorrow we'll wire an existing relay to 24 V to check this point (don't worry because we won't fry the control board).

The machine we're modifying is an Enshu DT-CL.

Anyway, many thank, you're really kind.

Dear,

We have wired a pair of relays with no changes.

If this could help you, find in the following photo the relays blocks that our machine uses.

https://www.cnczone.com/forums/attac...d=438270&stc=1

Best regards,

Those look like relay boards and of course those clear cased things along the top of both boards are your physical relays. The terminal boards are laid out nicely and labeled well.

Understand that all Y outputs are coming to that board on the flat multi-conductor cables. And the X are returning to the control on them.Without seeing the electrical schematic, I would try to figure out if the Y marked terminals are series connected through the relay coils or terminating at the switch arm of the relay. If they are through the coil, then when you activate a usable and working M code, you should see 24 volts on the corresponding Y addressed terminal screw. If you find it there with a volt meter, likely grounding that screw to the N wire would activate the relay. Then you would connect your new device to the the switching side of the relay. Note the red wires are likely 100VAC and the blue 24VDC.

If you cannot get 24volts to appear at the screw terminals, then those spare M codes my not be available. Your schematic and connector pin out sheets should tell you everything you need to know. The fact that the terminal strip is there and labeled so well makes me think that those inputs and outputs should be available for your use.