+5 V LED (Power Indicator Light) on BNC-2110 of PCI-6110 is off

[flyfar]

Hi All, 

My +5 V LED (Power Indicator Light) on BNC-2110 of my PCI-6110 turned off (as well as the 5V supply) after I mistakenly connected the +5 VDC power supply on my DAQ to an AI port. (See below) 

I have waited for some time and turned off/on the whole PC but the LED is still off and I do not get 5V. 

My questions are:

1) What is the likely reason for this malfunction?

Some manuals warn against connecting the +5V to DAQ inputs. This circuit does not need much power so it didn't need the +5 VDC supply and in retrospect, I could have used one of the Digital Output pins. Is this the best practice? What should I be avoiding in future circuit designs?

2) Is there an easy way to fix this, other than sending the DAQ card back to NI?

3) What potential damage might I have done? 

I have Self-tested the DAQ board and it reports that it is good. I also verified that the Analog In port that I used still reliably reported -10V to 10V. The only thing that seems to be wrong is the +5V supply. 

Thanks in advance!

FL

[Princealimagicalhe]

Flyfar,

 So there are some issues with putting in 5 Volts in AI ports because of how power is routed within the device. 

Have you been able to check the power supply with some other device and see if it's still functioning?

Additionally, have you tried your system with a new LED and see if you can narrow down the issue. It does not seem like your PCI-6110 is working but I would like to verify through multiple methods if possible.

Regards,

Ali S.
Applications Engineering
National Instruments

[Princealimagicalhe]

Flyfar,

 Additionally, when you said "some manuals warn against connecting the +5V to DAQ inputs". Is there a specific manual such as the PCI-6110 or are you talking about general DAQ devices? This is a broad application issue and it'll be easier to go from the specific hardware and then move on to best practices depending on hardware.

[flyfar]

Hi Ali!

Thanks for looking into this issue.

I tried using a different BNC-2110 with the same PCI-6110 and the LED still remains off. 

Other than the internal +5 VDC supply, all functions of the board seem intact, including digital I/O and analog I/O.

The PCI-6110 manual, page 4-15 reads:

Caution Under no circumstances should you connect these +5 V power pins directly to analog or digital ground or to any other voltage source on the 611X device or any other device. Doing so can damage the 611X device and the computer. National Instruments is not liable for damages resulting from such a connection.

Again, what potential damage might I have done? And is there an easy way to fix this, other than sending the DAQ card back to NI?

Thanks again!

-Ingie

[Princealimagicalhe]

Ingie,

 I looked through internal documentation for the PCI-6110 and although there isn't a single answer for why it would cause issues at that system, ultimately the internal circuitry was determined by our R&D department to be sensitive enough to cause issues in that voltage range as you mentioned.

Since you've already done a fair bit of troubleshooting and since the self-test came back successful, I think contacting National Instruments support would be the best next option. That way they can give you any additional troubleshooting steps over the phone (which might be easier in this scenario) to first ensure that you don't have to send your PCI-6110 for return. Additionally, if our support and return department still believes there is an error, they can at least give you a complimentary quote.

Please let me know if you have anymore questions on this issue or any questions on the support process!

NI Product Support:

http://www.ni.com/en-us/support.html