MACH3 and MPG Pendant

This forum is dedicated to those Hobbyists Interested in CNC machining in their home shops. (Digital Read Outs are also topical, as is CAD/CAM as it relates to CNC)

Moderator: Harold_V

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Wed Jul 15, 2020 3:08 pm

There would have to be something to sink that current on the parallel port IC. There are current limiting resistors between the logic transceiver and the port, which should limit to ~100mA. The transceiver chips are rated to 50mA max output current, and I believe there are also resistors inline on the parallel port IC inputs, and a diode on the supply input to the BoB. I'd think 100mA would take out the transceiver and parallel IC. 100mA would explain the toasty resistors though, but why?
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Wed Jul 15, 2020 5:47 pm

Well, now I've ordered a MP9715P-2 card with the nv9805cv chip and when looking for drivers, Google found the same driver that I installed for the card that I already have. It's not the same card, but now I'll have to check the chip. Might be bummed if it's the same... Maybe I can just bump up the IO resistor values on the BoB...
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

hanermo
Posts: 51
Joined: Tue Oct 01, 2013 5:47 am

Re: MACH3 and MPG Pendant

Post by hanermo » Wed Jul 15, 2020 8:09 pm

My €0.03..
1.
the pp pendants are basically a waste of time.

Because the signals are polled at low speed, 25 kHz, rely on catching state changes, and often have hw issues as you have seen, they have nothing to do in terms of functionality with real pendants.

Ex.
A PP MPG wheel, will have high and variable latency, for each pulse.
So it sometimes works ok, sometimes weak, and you have a "mushy" slow control path.

2.
GOOD hw controllers can deliver exceptional MPG control.
Sometimes for little money.
Pokeys (e) is one such piece of kit.
It delivers exceptional hw-based mpg and jogging functions, (+probe, homing, encodders etc).
Excellent value for money.
I use it on my 100k€ VMC, scratch built.
For less than 200€, very good value.

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Wed Jul 15, 2020 10:07 pm

So you're saying the $100 wireless MPGs on ebay would be ng either?

Pokey has the same pendant that I have, without the extra E-stop and other button. PP would seem to be a hardware interface whereas Ethernet and USB would be software.

Is the MPG inputs handled in the controller directly and then passed to the control SW? (MPG->controller->step drivers and MACH3) or (MPG->controller->MACH3->step drivers) i.e., can drive the machine without the PC on.

I guess PoKeys57CNC would be all I needed. I think my pendant is good, feels good and all I really need. I can add buttons if I need, looks like there are extra wires in the cord.
Hey, does that mean I could use the PC in my house from a network connection to the controller?

There is a US supplier. Hmmm... more money is always the solution.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Mon Jul 20, 2020 7:48 pm

A different PCI to Parallel port card did not change the behavior, which I am getting that in order for pins 2-9 to be used as input pins, you need an EPP compatible card, which both cards should be. Remember, my original card worked a couple times.

This isn't an issue with the BoB as setting MACH3 to use pins 2-9 as inputs sets the pins high, and I can see the LED indicators in MACH3 all light up, and shorting the port pins with a resistor does not make them go off like they should. Pins 10-13 + 15 do go off so the card is configured correctly. It may be a driver issue or software issue. I tried finding another driver and none will install.

That's all I got for this.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Mon Jul 20, 2020 10:54 pm

well, one more. I swapped ports and tested the MB port inputs in both ECP and EPP mode. ECP will light up the pins correctly, but it still does not toggle off when grounded.

I've been reading about some issues with the Pokey's interface. Of course you're going to have that. Looking at UCCNC or Pokeys, or even LinuxCNC with parallel ports.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Sun Aug 02, 2020 11:05 am

I stumbled on a new open box PoKeys57CNC on ebay, so that is on it's way. I don't like the way the pendant is wired because I will have make my own interface cable to swap some of the wires.

Does anyone know what kind of plug is for the e-stop? 4-pin header with adjacent pins offset; or maybe it's an 8-pin dual row header with 4 pins removed?
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

User avatar
ctwo
Posts: 2850
Joined: Tue Mar 27, 2012 12:37 pm
Location: Silly Cone Valley

Re: MACH3 and MPG Pendant

Post by ctwo » Wed Aug 12, 2020 2:13 am

The PoKeys57CNC came in and the basic configuration was complete on a backup PC. I only tested a couple of the motor ports and the limit switches.

Then the pendant setup took hours. Pokeys manual does not get into much of any detail, and even his pendant page provides very little. I found this manual helped a lot more (which looks like one of his, but not found on his site!?):

http://www.t2cnc.hu/downloads/PoLabs/Ma ... Manual.pdf

Now I have the pendant switching the jog mode on/off by using the axis selector; it switches the increment using the increment knob, and it will jog the selected axis with the encoder.

Since my pendant does not have the redundant "enable" button nor an e-stop, I had to modify some of the setting, and this might be causing some of my problems:

I had to switch the reset pin function from Reset to Enable Axis (something like that), and I have the e-stop inverted and running open circuit. This might be the reason that I am not able to access the Auto button and MPG div fields (grayed out). Maybe setting up the e-stop to NC will enable those features and also stop random e-stop/limit switch triggers, but there shouldn't be much noise just sitting on the table away from the PC with nothing else connected.

An odd thing is, when an MPG axis is enabled I cannot zero the DRO. Sometimes when I switch the MPG axis to off, the axis will zero. Maybe it was a delayed result but it seemed inconsistent anyway. I was also getting a LAN disconnected balloon from Windows, which is probably the least encouraging thing I could see.

I have not figured out the "Pendant mode" or the "let pokeys handle MPG jogging" toggles yet - they did not seem to have an affect. I'm also kind of lost in the pulse generator dialog that he presents in his manual, but I get the idea that comes from additional software for more of his driver hardware, which I'm not using (using Gecko drivers). I'm also confused about this Pokeys pin numbering. He has pins 1-55, but I cannot figure out how they map to an actual pin on his board.

Anyway, more progress than with LPT MPG port on that front. I'll have to do up some ribbon cable to screw terminal interfaces and find out whatever that red e-stop plug is - I suspect some kind of European plug.
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

BClemens
Posts: 468
Joined: Sat Oct 08, 2016 10:04 pm
Location: Gloucester, VA (Sassafras)

Re: MACH3 and MPG Pendant

Post by BClemens » Sun Mar 28, 2021 9:25 pm

Hope this was sorted out... I had many issues with the C22 CNC4PC pendant interface card - many issues. It would work great one day and not another. I threw in the towel with the interface and the pendant. Go to Vistacnc and check the iMach III - it is USB and boots with the computer not Mach3 and interfaces with Mach3 when booted. It has been a breath of fresh air to have a working (every time) pendant!! Great product - vistacnc.com
BC

Post Reply