Spare M Codes Question?

[AMCTony]

I have a TL-2 Lathe. Does anyone know how to hook up things to the spare M code terminals in the machine control cabinent? I want to hook in a pnumatic valve to operate an air collet chuck. Are these just switches or are they powered. What voltage/amperage is on these or are they capable of switching? Any help would be appreciated.

[Geof]

You can buy the wiring harness from Haas; installation included it should be around $200.00. This plugs into the relay and has a DIN socket that goes in a hole in the cabinet. You have a choice of M121 which activates the MFIN function that looks for a contact closure before the machine will continue or one of the other M codes one to turn the relay on one to turn it off. The relays are just contacts closing (or opening I think) that can switch an amp or two at 120V it is given in the manual. I had some control boxes made which have a 12volt power supply that uses the M code relay in the machine to switch a heavy duty relay in the box to operate a 1 or 2 hp motor.

[automizer]

The wiring harness from Haas I can't seem to find this option on there web site for information. What are the specs on this?

[Geof]

Originally Posted by automizer The wiring harness from Haas I can't seem to find this option on there web site for information. What are the specs on this?

http://www.haascnc.com/option_detail...&PartID=837#TL

Not much in the way of specs.

The relays and user M functions are in the machines; M21 on mills for the MFIN, M121 on lathe. The only part missing is the socket installed on the control cabinet. Before around 2003 it was installed but then I think they cheaped out and made you buy it separate. If you go to the link you will see my memory is faulty, the price is $99.00.

I do need to mention that if you have a machine with some options such as tailstock and barfeed interface on the lathes all the standard user M relays may be taken for these options. In this case you have to get a second relay board installed and programmed and that is more than $99.00; I think you need to put a zero on.

[AMCTony]

In my cabinet there is a relay block with M21, M22, M23, and M24 slots. There is nothing attached to any of these. I want to use these to switch a Numatics Mark 8 valve. The valve is 24V at 0.25 amps (6 watts). This should be no problem to run straight from the M function block but with what these boards cost in these machines, I would like to be sure of this.

[Geof]

Originally Posted by AMCTony In my cabinet there is a relay block with M21, M22, M23, and M24 slots. There is nothing attached to any of these. I want to use these to switch a Numatics Mark 8 valve. The valve is 24V at 0.25 amps (6 watts). This should be no problem to run straight from the M function block but with what these boards cost in these machines, I would like to be sure of this.

Yes, I think you will need a 24 volt power supply and then the relay in the machine can control the valve directly. Because the relay is an inductive load you need a free-wheeling diode to protect the relay contacts when they open. I think another name for this is a snubber. You can probably guess I am a bit foggy in this area, I had an electonics guy build my little boxes that I mentioned.

If you use the M21 etc then you also have to provide for the MFIN signal; this is described in the manual. Also on lathes the code is M121 even though the relay may be labelled M21.

[AMCTony]

Thanks for the input. You wouldn't happen to know if that diode is built into the mfin cable from Haas? If it is then that is probably the route to go since I know enough electronics to be dangerous.

[Geof]

Originally Posted by AMCTony Thanks for the input. You wouldn't happen to know if that diode is built into the mfin cable from Haas? If it is then that is probably the route to go since I know enough electronics to be dangerous.

No I just remember reading in the manual something about protecting the relay contacts when switching an inductive load. I will look for the page in the manual and scan it.

[Geof]

Here is the info from the manual. You will see it says the socket is installed but in fact on your machine it isn't; Haas stopped installing them a few years ago.

[serviceman]

you really do not need the 4 pin din connector from haas you can wire directly to the m21 -m24 terminal blocks on the io board on the top right. the din connector is really made for the prewired m code cable for using with the servo control and you really do not need the m-fin if you are just closing a contact and not waiting for a finish signal. you can fire the m codes with m51 and m61 m52 m62 etc. on and off respectively. they should be labelled com no and nc common normally opened and normally closed this is just like a light switch basically haas does not supply 24vdc so you would need a power supply or get one that is 12 vdc or 110 vac then you can tap off the existing power in the machine you should be able to switch about 10 amps at 110 vac with this relay, but i would probably stay lower than 10 amps. the 24vdc solenoid that you have should be fine for the contact.

[serviceman]

top left

[AMCTony]

Just talked to Haas today. They said that if I am switching a load with an AC circuit then no diodes are needed. I switched my valves to AC selonoids. They said that the switches in the Haas are good to 120V AC and 1 amp. Another quick fix to protect the I/O board that they recomended would be to just use another relay with diode protection and have the Haas switch the relay. This way if the extra relay were to get destroyed it could be replaced cheaply instead of the I/O board.