Spare M functions

[1ctoolfool]

The spare M function option, does this actually come with control enabled relays and what are the specs of the relays? Just 110V simple on/off relays?
Where is the interface? Just plug into the control box in the back?
Thanks,
Joe V.

[Geof]

There are relays already installed on the board in the control cabinet. Older machines came with one relay connected to a DIN plug on the side of the cabinet but since about 2002 this has not been included; the cost installed (at least from my dealer) is around $100.

The relays on the board are small and I think (don't do anything without confirming this) that they are okay for 120 VAC but they are very low current rating. It is more or less essential to have them simply switch a larger relay external to the cabinet for controlling motors, etc.

We have a few machines set up with external motor control using the M function and have relay boxes. These have a 12volt DC power supply (wall wart) and a decent sized 120 VAC relay with a 12V DC coil. The machine relay just switches the 12V DC supply to operate this relay and because this is DC to protect the machine relay contacts from arcing a snubber diode (freewheeling diode) is across them.

Some of the relays already in the machine may be used by different options; this is often the case on lathes with barfeeds. On the mill there are fewer options that use them. It is possible to get a second bank installed for about $1200 or so.

The location of the relays in the cabinet is in the upper left corner. I could get a photograph if you are stuck finding them or maybe someone else already has one. There was a thread about hooking up something to these relays a few months ago.

[1ctoolfool]

thanks Geof, if you pay for the spare M functions do they include some type of interface board to connect to the relays or is it bare wire type screw terminals or what?
thanks
joev

[Geof]

Originally Posted by 1ctoolfool thanks Geof, if you pay for the spare M functions do they include some type of interface board to connect to the relays or is it bare wire type screw terminals or what? thanks joev

I think each relay on the bottom has screw terminals for the relay contacts: C, NO, NC.

And you don't need to pay for the first M functions they are included, it is just the cable and socket that is omitted. You can always install your own socket; I just find it convenient to get it done for me, the cost is reasonable.

I will take pictures inside one of my machines tomorrow if you like and identify the relays. Bug me with a PM if I forget

[serviceman]

you normally get 4 m codes in the fully stacked io board most tm-1's and mini mills do not come with 4 they come with 2 m codes. the jack on the side of the machine you really do not need unless you are running an m-code operated servo control. the only reason for that is the m fin signal which you can still get from the io board without the connector. if you only want to fire an m code you tap into the realys on the top left of the io board they are labelled. if you need more than the m-codes supplied with the machine you can get the 8m option which will give you 4 more m codes for a total of 8. i probably would not run more than like 5 amps at 120vac if you need to switch something that draws more you should use a contactor and fire the coil with the m code.

[Geof]

Here is the picture and a link to another thread on this same topic:

Spare M Codes Question?


I may have mislead you a bit saying the relays are in the upper left....they are in the upper left corner but on the bottom board.