How check proximity sensor good on commissioning

Hi all,

I am working through initial commissioning and have got as far as checking functionality of the duet board - comms is good, temp sensors reading correctly. Good.

But am not sure if I have a real problem or not: whenever I plug the proximity sensor cable in (with the green and yellow wires), the USB hub I am using shuts off the supply after 3 or 4 seconds, presumably due to overload. I am measuring around 280 ohms between the green and yellow connections when unplugged. Is that correct?

So not sure if the hub is just not up to the job, or if there is an issue with the sensor. Would be nice to know before the first switch on of the main PSU.

Thanks,
Ralph

Did you resolve this? It sounds to me that either the proximity sensor board is faulty (e.g. the tantalum capacitor is installed the wrong way round), or the proximity sensor loom is wired incorrectly (does the order of the coloures wires match the photos in the wiring instructions, at both ends?), or you have one of the connectors the wrong way round.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi,
Thanks for the reply - and no, not sorted yet.

I have checked the plug and wires are in the right order, but will look at that again, as I know how sometimes simple things can catch you out!

Ralph

Hah - yes, simple things.

The connector for the sensor on my loom has: Red,Green,Blue,Yellow. And I can see on the instruction photo it is: Red,Yellow,Blue,Green.

So I guess there's my problem.

You can swap the wires round yourself. At the sensor end of the loom, use a tiny flat-bladed screwdriver or the point of a knife to lift the black plastic tab slightly, then you can pull on the wire to remove the crimp pin. The re-insert them in the right order. However, the tantalum capacitor on the sensor board may have been damaged by having voltage applied in the wrong polarity, so putting the wires in the right order may not solve the problem.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks dc42. Checked that connector several times, so no idea why I didn't spot it before - colour dyslexia perhaps!

All sorted. Have now completed the commissioning steps - heaters working, motors moving and the proximity sensor reading correctly.

So thanks for the nudge.

Ralph