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Author Topic: C11G PWM control voltages go down when increasing speed in Mach3  (Read 2128 times)

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I have installed a CNC4PC C11G board and set up Mach3 as per the C11GS R1.5 Mach 3 settings (the boards are largely the same and there were no Mach 3 settings in the C11G r9 manual. )

Spindle turns on no problem with an M3 command and I can vary the speed but the spindle rotates slower when I increase the speed in mach 3 and goes faster when I decrease the speed in Mach3. The voltages on the 0-10v pin that connects to VI on my spindle go up when decreasing speed and go down when increasing speed - ie backwards to what they are supposed to. I am sure I just have a setting incorrect or some terminals incorrect.

Any ideas where to look? I am stumped   

Using a Huanyang VFD
« Last Edit: August 24, 2017, 06:46:24 PM by Lindzr »

Offline Tweakie.CNC

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Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #1 on: August 25, 2017, 01:50:54 AM »
Try check (tick) Step Low Active for Spindle in Ports and Pins.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #2 on: August 25, 2017, 07:54:51 PM »
Tried step low - same thing but thanks for the idea. The spindle slows down if I increase the speed in Mach 3 or speeds up if I decrease the speed. The scale is off quite a bit too in Mach (10000 rpm is 16,270 on the VFD readout) but I can probably adjust the pulley ratio or change the min max voltages in the spindle parameters to fix that.

I need to get the speed thing fixed first before tuning it - What setting(s) in Mach would I change or invert to modify this behavior?
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #3 on: August 25, 2017, 08:12:38 PM »
Hi,
tweakie has already told you

Config/Ports and Pins/Motor Outputs---reverse the Spindle Step Low Active setting.

Craig
My wife left with my best friend...
     and I miss him!
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #4 on: August 25, 2017, 08:42:37 PM »
As I said in my 2nd post I tried that and it doesn't do anything different, the spindle still works incorrectly - slows down when I increase speed in Mach3. I am using PWM not step and direction spindle speed control if that makes a difference. Any other suggestions?
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #5 on: August 25, 2017, 08:49:34 PM »
Hi,
do you have a multimeter? If so measure the voltage at the pin.

It should change if you reverse the polarity of the PWM signal.

What pin are you using for the output? Could it be a pull-up or pull-down signal which is confusing the issue?

Craig
My wife left with my best friend...
     and I miss him!
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #6 on: August 25, 2017, 09:10:47 PM »
Hi,
I'm looking at the C11 manual. On page 7 it shows that pin 14 should be PWM output pin.

Section 7.2 page 10 shows an LED installed across the output. With the recommended IEEE 1284 pull-up at the input then the output buffer should be
low in absence of PWM, ie the LED should be off.

The LED should increase in brightness as the PWM duty cycle increases, ie Mach demands increasing spindle speed. Is This what you see on the board?

Craig
My wife left with my best friend...
     and I miss him!
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #7 on: August 25, 2017, 11:29:26 PM »
I am not at my shop right now but if the IEEE 1284 spec vs standard printer port spec makes a difference in terms of the PWM signal that could be my issue IF the IEE1284 spec would literally invert the signal somehow vs std printer port.

The C11G board has a jumper for "1284 compliant" or "not", and my board is set to not compliant. I was not sure if the UC400eth was 1284 compliant. I even emailed their tech support and got an answer that cut and pasted from the manual that was not all that clear to me. see below. I interpreted it to be saying a standard printer port but maybe I will email again to be sure. I am not sure about the LED dimming and brightening (there are tons of leds that light up on the board) but I measured voltages going to VI on the VFD and they go down when I increase speed in Mach3 so I was assuming the signal was inverted from Mach, not that there was a possible issue with the board setup. see below for jumper section of manual on board as well as my correspondence with their tech support

Hi
 
I have a new bob with a jumper for IEEE 1284 compatibility
 
what I should set it to for the UC400ETH? – I see no mention of IEEE 1284 in the manual but want to be certain
 
Thanks!


Dear Lindsay,

In the manual you can find information about it on page 18-19.:
http://cncdrive.com/MC/UC400ETH%20datasheet/UC400ETH_manual.pdf

"There are 2 pieces of IDC26 I/O ports on the board. Both ports has the same pinout. The pinout is the same as the pinout of a standard LPT port in addition the 26. pin (there is no 26.pin on the LPT port) has a 5Volts power output."

"Plugging a IDC26 to DSUB25 female crimped cable to the IDC26 ports the DSUB25 port will have exactly the same pinput as the standard LPT printer ports on PCs."

Best Regards,
              Csaba Nemeth
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Csaba Nemeth
25 Pafrany utca, Pecs, 7633 Hungary
Tel.:+36-70-932-0327
http://www.cncdrive.com
http://www.cncdrive.hu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


« Last Edit: August 25, 2017, 11:46:41 PM by Lindzr »
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #8 on: August 25, 2017, 11:46:54 PM »
Hi,
I think that maybe you should disconnect the VFD for the moment. Until you get the voltage from the BoB sorted it will only confuse you.

Double check that the pin you are measuring is pin 14 and that you have identified the LED that reflects its current output state.

You say you are using an ETH400, then you have another whole board in the system that we did not know about. Do you have an oscilloscope?
I think your going to have to probe the input to the BoB, I now suspect the ETH400 is producing a signal of inverse polarity. I'm guessing
or perhaps hoping that the ETH400 has a setting in its plugin which determines the polarity of the PWM signal.

Craig
My wife left with my best friend...
     and I miss him!
Re: C11G PWM control voltages go down when increasing speed in Mach3
« Reply #9 on: August 26, 2017, 12:51:19 AM »
Disconnect VFD - noted. Will do so tomorrow. That said it is easy to see/hear if it was speeding up or slowing down rather than probe and watch my my meter

The UC400eth plugin is not like the ESS with a bunch of adjustable specs in the plugin interface. It just installs as is and there is not much you can change in it as far as I know. I will look again tomorrow to double check. If you have ever used a UC100 USB adapter the plugin is very similar. Installs with a windows installer and that's it.

I do have a scope but never really learned to use it but this might be a chance to try and learn how to do something with it. Maybe let me know what I should probe and look for -

That said is there not a way to invert the signal from Mach if that is the case? or perhaps change something in the XML? I did see a thread here where someone had a similar inverted signal issue where checking Step low active changed the signal as You and Tweakie suggested.. Unfortunately in my case it does not seem to.

The other thing I thought of was that I might be able invert some settings on the VFD assuming there is nothing I can do on the board/plugin/Mach?? Of course I was reluctant to do that and blow up my spindle due to my ignorance of what can and cannot be done in the various parameters. It's a Huanyang 2.2kw FYI if you think that is worth trying

Thanks again for all the help