[CapnC]

I am struggling with an intermittent problem. I have a Kflop along with a Kanalog board. Connected to the Kflop are three G201x Gecko drives and on the Kanalog I have a Torch height controller connected to two optoisolated outputs and an Emergency stop button connected to the one of the optoisolated inputs and the arc ok signal to another optoisolated input. The boards are powered by the USB port.

The problem I have is sometimes when I plugin the USB plug to my computer the two Kflop Leds blink then stay on for 2 to 3 seconds and then shut off and once again blink then stay on for 2 to 3 seconds. When this happens I've tried plugging the USB cable into different USB ports but get the same results. After I unplug and plug back in the USB cable a few time the Kflop boots up and the LEDs stay on and everything works fine.

Another way I get the kflop to boot up is unplugging the USB cable then unplug the kanalog form the kflop then plug back in the USB cable to the computer. The kflop boots up fine. Then flash the Kflop. unplug the USB cable, plug the kanalog back in and plug the USB cable back into the computer and it all boots back up fine.

With a multimeter I tested the outer part of the USB plug with respect to ground and got a reading of 100v. So I noticed the PC was not ground. I grounded the PC now get a reading of 1v. Still the problem comes back intermittently. It mostly happens when shut down everything the PC, kflop and drives come back the next day boot up and Kflop keeps rebooting.

Anyone have any suggestions.

thanks,
Bradley

[TomKerekes]

Hi Bradley,

Using USB +5V Power for KFLOP+Kanalog is marginal. Remove KFLOP jumper J3 and use an external +5V regulated supply to apply +5V to KFLOP or Kanalog.

Regards