RSL light not turning on

We are having a problem with our RSL light. The RSL LED on the roborio works perfectly, but the RSL bulb does not turn on.

We have tests cables and light bulb with 12volts, and everything was fine.
We have replace Roborio with last year’s firmware and the light is still off.

When we put the voltmeter at the RSL poles from the Roborio, we do not get any voltage in any of our 2 Roborios…

Ideas?

If I understand you correctly, you don’t see a voltage across the RSL pins on the roboRIO when measuring with a voltmeter. But when you plug in a standard 12V incandescent light bulb, it lights up. These observations logically conflict with each other. If that’s the case, I believe you have a broken voltmeter or are using it incorrectly.

If that’s not the case, can you please try explaining your situation again.

No, the light bulb does not turn on when connected to any of our Roborios.

We tested the light bulbs and they work.

Ahh that makes more sense. If the RSL light on the roboRIO turns on but the pins do not have a voltage, then it sounds like the RSL pins are broken on your roboRIOs. I would contact NI support when they open on Monday and see if they have any ideas for fixing the problem yourself. Otherwise, you may have to send the roboRIOs to NI to get fixed.

Both Roborios would have the same issue?

It’s unlikely but possible. I don’t know how short-tolerant the roboRIO RSL pins are. It’s possible that you connected a RSL with shorted wires to both roboRIOs and that damaged both of them in the same way.

Other than that, I can’t think of anything to explain the symptoms you described. Maybe someone else on here has an idea.

What color is the power led on the roborio?

Solid Green.

To wire the rsl, the two outside leads have to be jumpered together, and then positive goes to the outside jumpered wires and ground goes on the inside terminal, obviously that makes no difference if your roborio is not sending voltage and is damaged, but for future tests, make sure it is wired correctly as described above. The rsl will not turn on if the jumper is not in place.

Yep, we got several bulbs wired like that.
Still checking cabling.

We have seen this behavior several times when we have an electrical short to the chassis.

Our usual troubleshooting procedure is:

  1. Remove all breakers from the PDP, and unplug the VRM and PCM (or pull the VRM/PCM fuse from the PDP).
  2. Verify the RSL turns on. If not, check remaining wiring (battery to main breaker to PDP; PDP to roboRIO, any PWM/DIO/AIO/relay plugged into the roboRIO) to ensure no shorts to the chassis. If necessary, unplug all roboRIO inputs/outputs as well, then include them in the one-by-one reattachment in step 3.
  3. Plug in one thing at a time (VRM, PCM, breakers one by one) and verify that the RSL turns on/remains on after each thing has been plugged in.
  4. When you plug something in and the RSL does not turn on (or turns off) inspect that branch circuit for shorts to the chassis.
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If the rsl led on Rio is correct, try wiring to a the rsl with two short pieces of wire without jumper. You should be able to connect the rsl directly to voltage and get it to turn on. I am assuming you wired the jumper. Make sure the jumper is wired correctly, you may be shorting the Rio output.

We don not know what was the issue. It started working out of the blue…
We went to Midwest with that setup with no issues.

Thank you for the help!

Do a pull test on both ends of the wires between the Roborio and the RSL. Test one wire at a time.

This would tend to support @TPC’s idea that you had an external short - and that was “fixed” during shipping.

The RSL will light up w/o the jumper. It will however continuously flash even though the robot is not enabled if the jumper is not present.

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correct, my bad

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