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Author Topic: pmdx411 cannot communicate with device  (Read 152 times)

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pmdx411 cannot communicate with device
« on: February 28, 2019, 07:15:17 PM »
Using pmdx411 - g540 and Mach4 lathe

Switched out my lathe spindle controller for a MC-60.

After about 10 seconds of run time at any speed the spindle stops.  G540 is still green and no disabling of Mach.  When I do hit the disable button, PMDX throws a 'Cannot communicate with device' message.  I have checked all three wires for continuity and connection status.  MC60 shows it is providing 11.32volts at the g540 vfd+ and vfd Ground connections.

I have it set up with manual switches to go from Mach controlled and manual potentiometer controlled and the MC60 runs the spindle smoothly for any speed and duration using the potentiometer. 

Any suggestions as to how I should proceed do to track this problem down?

TIA

RT

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Re: pmdx411 cannot communicate with device
« Reply #1 on: February 28, 2019, 08:59:01 PM »
Probably the new MC-60 motor controller is noisy and wigging out the G540, PMDX-411, USB or all of them!  I would put some chokes on the MC-60 wires close to the G540.

Steve
Re: pmdx411 cannot communicate with device
« Reply #2 on: February 28, 2019, 09:04:07 PM »
Steve, thanks but I am an electronics idiot.  The mc60 is 5 ft from the g540.  Does that make a difference?

I will google for what a choke is

Tia
RT

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Re: pmdx411 cannot communicate with device
« Reply #3 on: February 28, 2019, 09:21:59 PM »
A choke is basically a device to prevent common mode currents on the signal lines.  Usually, all it consists of are ferrite cores.  Such as https://www.mouser.com/ProductDetail/Fair-Rite/2643625002?qs=MLldULe7zY2ZDvtexqlGbA%3D%3D.

Pass the wires from the MC-60 through the core (as many turns as you can fit).  Do all three of them.  It is important that the choke is as close to the G540 as possible.  Say within an inch or so.  Meaning it doesn't have to be .0001 close!  :) 

http://www.w6pql.com/images/hf/hftkctrl.jpg

In that picture above, the heavy pinkish/red wires are passed through some larger cores.  And then there are a lot of signal wires or different colors being choked as well. 

Steve
Re: pmdx411 cannot communicate with device
« Reply #4 on: March 01, 2019, 04:40:03 AM »
Hi,
I had problems with a customer who had an HF start plasma table with the PC some 20'-30' away.

The winning strategy was to put ferrites on the cable, but in three locations, approximately equal distance apart.
I reasoned that the cable was behaving like an antenna. By putting ferrites on it, it broke the antenna from one long
one to four shorter ones.

The customer tried one at each end and while it helped it still wasn't right until he put a third one on.

Craig
My wife left with my best friend...
     and I miss him!
Re: pmdx411 cannot communicate with device
« Reply #5 on: March 13, 2019, 03:34:52 PM »
Just wanted to update.  Got the ferrite cores and installed per Steve's direction and that solved the problem.

Thank you!!

RT

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Re: pmdx411 cannot communicate with device
« Reply #6 on: March 14, 2019, 02:37:48 AM »
Don't you just love it when something works?  :)  Ham radio to the rescue!!!!

Steve