MPG/Pendant wiring info sought

[Brian Kidd]

Currently I am still in the middle of my IH Mill CNC conversion. Eventally I will probably make an MPG/Pendant. I have the Campbell Combo board for my breakout but with that if I hook up an MPG to it I loose my limits for my A and Z axis which I would really like to retain for obvious reasons. I will be running the Campbell board through an add on Parallel card so I will still have a free parallel port to use. With that said is there an economical way of using a different board and the free parallel port to hook the MPG/Pendant up to? BTW I will be running Mach 2/3. I still have a lot to learn in the electronics so forgive my noob question. The MPG I was thinking of using is the one advertised on Rogers machine: http://www.rogersmachine.net/MPG/heatsink.html which has 100 steps to it. Is this sufficient or should I use something with more steps?

Thanks
B.Kidd

[Al_The_Man]

Originally Posted by Brian Kidd Is this sufficient or should I use something with more steps?

All commercial MPG's I have come across have 100p/rev
Al.

[Brian Kidd]

Originally Posted by Al_The_Man All commercial MPG's I have come across have 100p/rev Al.

Thanks Al, so it looks like this one would be a good one. So now I need info on connecting it up.

Thanks
B.Kidd

[ger21]

Get another breakout board, like the ones from www.cnc4pc.com for $25 and hook it up to that.

[Brian Kidd]

Originally Posted by ger21 Get another breakout board, like the ones from www.cnc4pc.com for $25 and hook it up to that.

Ok that looks like it might be a winner, I've looked at the CNC4PC breakout before I settled on the Campbell. Felt the Campbell was a better board for at least the interfacing with the Geckos and such but I think the CNC4PC board might be the right ticket for hooking up the MPG/Pendant to. Doe's anyone have a basic schematic for a Pendant. I am not sure exactly what to wire to what as in the switches for the different axis and other things that might be required.

B.Kidd

[ger21]

It really depends on what switches you want to use, for what functions.

[Brian Kidd]

Originally Posted by ger21 It really depends on what switches you want to use, for what functions.

Oh I relize that I was just wondering what the minimum basic switches are required, I know like mentioned Axis switch, probably an E-Stop, power? anything else.

Thanks
B.Kidd

[ger21]

THere's no minimum, and no limit. Just put whatever you want on there. If you have an MPG, you'd want an axis toggle, as well as a jog mode switch. Most have an E-Stop. After that, it's all up to you. ChrisD has a link to his here somewhere, with about 100 buttons and switches. There's also some info on the Mach3 Yahoo group.

[Brian Kidd]

Ok thats understandable. I did e-mail cnc4pc to find out the difference between what they advertise as "Parallel Port Interface card" and their "Bidirectional Breakout Board" which he replies:

"The Parallel Port Interface Card is designed to be used on the first port
(LPT1), inputs are buffered, that means they are not outputting the current
from your computer's parallel port, but the current from the external power
supply. That is to ensure you have enough voltage and amperage to operate
your devices. On this card inputs are optoisolated, that means there is no
physical connection between the signal coming into the card and the signal
going into the computer, the signals are transmitted though a small light
beam inside an IC.

The bidirectional breakout board has all input and outputs buffered. It also
has a jumper that lets you use pins 2-9 for input, that way you will get a
total of 13 pins for input and 4 for output, if you already had 5 pins on
LPT1, that will have a total of 18 pins for input. It was designed to be
used on LPT2. You can connect directly to it your MPGs, encoder signals
coming from your motors, limit switches, or external activation switches.

Sorry for the long explanation, I believe the bidirectional breakout board
is the one you are looking for.

Thanks,

Arturo Duncan"

Which confuses me a little bit in that what he says is I need the bi-directional board hooked into LPT2. Unless I can swap addresses LPT2 is the new parallel port card I installed to run the Campbell board off of just so I knew I had a good port for all the communications to the drivers and such. I wasn't as concerned using the LPT1 (the one built on the mobo) for secondary devices like the MPG. With that said does an MPG have to directly communicate with the computer without an opto-isolation or can it still communicate through an opto-isolated board? If it can it looks like I can still use their isolated board on LPT1. Clear as mud?


Thanks
B.Kidd

[ger21]

It shouldn't matter whether it's LPT1 or LPT2. I think he just meant that he designed as a "second" card, for switches more than for motors. If you want a lot of switches, then the bidirectional board is probably the one you want.

And the isolated or non isolated shouldn't make any difference, either. The MPG is basically just a switch .