sbRIO, no Ethernet after reboot with USB or SD plugged in

[tannerite]

I would also recommend making a Service Request with so you can speak with an Applications Engineer. That way, we can handle this through the standard channels.

[bef]

Hi Uwe,

I'm just curious how your problem was solved.

I'm experiencing the same problem with a sbRIO 9606. I'm not able to reproduce the error. Most of the times the Ethernet-LEDs are dead. Only sometimes (e.g. when plugging the ethernet cable during startup) the LEDs light up and I can connect with MAX.

I measure 36mV between housing ground and supply ground. I tried pulling the grounds together but that didn't seem to help.

Is there an easy solution for this problem?

Have a nice day!

[tannerite]

bef,

What is your grounding topology? Are you using a daughter card? If so, how are you connecting chassis ground, digital ground of the RMC, and power supply ground together?

[bef]

To be honest, for the first attempts I didn't mind grounding issues. I just hooked up the 9606 with the RMC and ran a couple of easy test VIs on the FPGA and the RT system. That worked fine.

Then I connected some signals to the RMC (and with that I made some GND-connections between different IO-connectors, like DI-ground and DO-ground). when I tried to start the system the ethernet-LEDs didn't light up and I couldn't connect to the sbRIO any more.

I didn't do any more tests with that configuration. I disassembled everything and connected only the sbRIO to power and ethernet. But the problem remained.

The strange thing is that I can get the board to connect in one out of 20 tries. But I can't reproduce that. Sometimes it works when I plug in the ethernet cable just after powering up the board. Then things work until the next reboot of the sbRIO.

I tried several grounding options, like tying power-ground to the ground-connector or to the ethernet-plug-shield. Sometimes that helps, but in most cases I just can't connect.

Have you seen this behaviour before? Could it be that something on the sbRIO is instable? Like the onboard power regulators? Just guessing...

[tannerite]

Were you using the NI 9694 to breakout the RMC pins? It sounds like your sbRIO is damaged and may need to be sent in for repair. Have you tried connecting a serial cable to the sbRIO to see if there are any errors during boot on the Console? If not, it may be worth trying as a last step. There is a risk that if you have the negative lead of the power supply connected directly to chassis (any of the shields) that this bypasses the reverse-voltage protection for the Ethernet ESD protection. Do you believe you could have plugged the power supply in backwards with chassis and ground connected?

Regardless, you probably need to call our support line to go through the process of repairing this unit.