Author Topic: MC050-010 Skewed input due to PWM output  (Read 5760 times)

Offline TheTurfDude

  • PLUS+1 Developer
  • ***
  • Posts: 37
  • Karma: +0/-0
    • Trebro Turf Equipment
MC050-010 Skewed input due to PWM output
« on: November 25, 2015, 11:20:52 PM »
Hello,

I am working with a 50 pin controller and have been having issues with my voltage inputs. In our system we have a DP720 directing the show and when run mode is enabled from the display outputs to certain valves come on.

What I have noticed is when any PWM output is on and a valve is consuming current, my voltage inputs jump all over the place  :o

This has induced quite the headache... This causes the moving parts of the machine to stop short or passed the position that it NEEDS to be at. Without a valve attached and PWM output on this problem goes away, so it has something to do with internal power supply.

Has anyone else experienced this or know of a better way? I am using pinConfig 4 on my outputs for PWM mA setting.

Any suggestions welcome. Thanks.

 ???

Offline Marbek_Elektronik

  • PLUS+1 Guru
  • *****
  • Posts: 315
  • Karma: +7/-0
    • Marbek Elektronik
Re: MC050-010 Skewed input due to PWM output
« Reply #1 on: November 25, 2015, 11:37:42 PM »
Hi,
what valves have you used?
In which way voltage jumps all over the place? Have you used an oscilloscope or a multimeter?
Marbek Elektronik, Dipl.-Ing. Bernd Konrad
Dienstleistung, Entwicklung, Herstellung

Offline FStelzer

  • PLUS+1 Expert
  • ****
  • Posts: 50
  • Karma: +8/-0
Re: MC050-010 Skewed input due to PWM output
« Reply #2 on: November 26, 2015, 02:24:11 PM »
Hello,

what is the max current consumption of the valves ?
And do you connect the last 4 Pins of the MC050 Controller with the power supply ?


KR,
Florian

Offline FluidPowerTom

  • PLUS+1 Guru
  • *****
  • Posts: 268
  • Karma: +20/-0
Re: MC050-010 Skewed input due to PWM output
« Reply #3 on: December 01, 2015, 08:42:56 PM »
I recommend monitoring voltage on various parts of the chassis and other wiring with reference to a known 0V ground.  My suspicion whenever something like this happens is a ground fault somewhere.
Mechanical Engineer
Hydra-Power Systems - Distributor - Pacific Northwest

Moe

  • Guest
Re: MC050-010 Skewed input due to PWM output
« Reply #4 on: June 03, 2016, 08:33:24 PM »
Are your sensor input grounds grounded close to where your coils are grounded i.e. battery bus in panel etc?
If so, you are probably inducing voltage from the PWM coil grounds, or even DOUTs if you're using them.

Try grounding all of your sensor grounds to Pin 9 (sensor ground).
Be careful not to exceed the load rating of the controllers sensor power supply. 450mA

Offline TheTurfDude

  • PLUS+1 Developer
  • ***
  • Posts: 37
  • Karma: +0/-0
    • Trebro Turf Equipment
Re: MC050-010 Skewed input due to PWM output
« Reply #5 on: June 25, 2018, 10:19:03 PM »
Thank you everyone for the replies and I apologize for the massive delay in response.

We were routing the ground back to the battery, tried what Moe suggested and ran ground to the sensor ground pin of the controller and voila! Problem solved.

I re-read my original post and realize it was not very clear. I am still new to this stuff but at that point in time I was extremely green.

To answer the other previous replies, We are using a Argos proportional valve.

What I really meant by "the voltage is jumping all over the place"- When the coils were supplied a signal from the controller, the voltage inputs would rise around 150-200 mV from their actual reading. Meaning, I did not mess with the sensor and the input voltage would "rise" when the valve was actuated, and "fall" back to its normal reading when the signal was taken away.

We do wire the last 4 pins of the controller to supply.

Thank you again, everyone.

Jake