GX io extender - output fault

Q&A and troubleshooting
, ,
21

Hi @Heraldo,

Can you provide some more details on the load you’re switching with the PWM output? Is it an inductive load? Or resistive? What is the power rating? In case it is an inductive load, did you apply a free-wheeling diode?

Best regards,
Rein

22

Hi Rein,

Sorry for the delay in responding, I was away on business but I’ll get back to you with the answer.

The loads I was testing were an LED light and a small motor. Both loads are 12Vdc 500mA aprox.

Previously, the same problem occurred with both resistive and inductive loads.

I don’t have a freewheeling diode connected to the motor, so that could be the cause of the problem in that case. However, the LED light was also failing.

I have now updated to the latest firmware version and the luminaire works perfectly with dimming.

Tomorrow I’ll go buy a couple of diodes to test the motor again and I’ll let you know how the tests went.

Thanks so much for everything.

BLUE POWER!!

23

Hi @Heraldo,

We did some testing with an AC load on the relay output and can confirm that this is definitely caused by EMI issues. You should prevent / mitigate EMI as much as possible:

  1. Use flyback diode on inductive loads to reduce back-emf.
  2. Route load cables away from the USB cable as much as possible to prevent noise being picked up by the cable.

Let me know if this helps.