PCI-6071 giving incorrect reading

[Dennis_Knutson]

We just received three new PCI-6071 cards. Using the test panel in MAX, for differential, RSE, NRSE, the reading returned is always the value whatever I specify for the high range. If I specify a +/- 10 Volt range, I get a +10 volt reading. Specify a +/- 5 volt range and all I read is +5 volts. Connecting the ai pins to ground makes no difference. One board that we got a couple of months ago does not exhibit this behavior. I have tried both NI-DAQ 7.0 and 7.1. I hate to think that we got three bad boards from NI but at this point I don't know if there are any other possibilities. They do pass the self test in MAX. Does anyone have any ideas? TIA

[JaredA]

Hello,

From what you just described, it sounds like you are using Test Panels to measure the levels of your AI without anything connected to them. This is common behavior because the inputs are floating in a high impedance state. Any current that passes through the high impedance state will appear as high potential on that signal. Knowledgebase 332957KD talks about this behavior.

If you are sure that you are connecting and measuring the appropriate analog input signal to ground, but still the railed signal, then it could be a case that there is a problem with the input amplifier. If you have all three devices installed, make sure that you are connecting t
he same device to ground as you are measuring in Test Panels. Then post back to this discussion with exactly what you are doing so we can make sure that there's nothing that we are missing.

Also, you can run the E Series Diagnositc Utility on your device to see if there's any problems.

Let me know how things work out.

Regards,

Jared A

[Dennis_Knutson]

I've tried it in differential mode with the inputs shorted and with both inputs connected to AI Gnd. I'm using a couple CB50-LP connector blocks. I get the same reading with inputs configured for both NRSE and RSE and analog in connected to AI Gnd. I'll try the diagnostic utility.

There is one thing that I find a little strange. As I mentioned, we had already received a daq board that functioned correctly. I just pulled that out of it's pc to see whether it would work in one of the new ones. The working daq board has a silkscreened copyright of 2001 and the non-working ones say 2000. The working one has an extra notch in the PCI connector (3.3V capable?), and the non-working ones are missing a small little daughter-board that is present on the
functioanal one.

[JaredA]

Hello Dennis,

I was able to get my hands on a 6071E to check out the discrepancies that you're talking about. My board is copyright of 1997, with part number 1884411B-01. It does have a notch in the PCI connector, as well as a daughter board which is located close to the 100-pin connector.

What is the part number for your device? It's possible that the revision of the device that you have was redesigned not to use the additional daughter board. If I pull the board off, there is a sticker on the back side with the label S280394-05. On the devices that are not work, is there a large void where you think the daughter board should be, or do you see some ICs soldered directly on the board? According to the silkscreen on my board, the connectors tha
t connect the board to the daughter board are labeled J4 and J5. (You wouldn't happen to have a digital camera to take a picture of the device, would you?)

I'll continue to work on this issue, to see what I can figure out. Get back to me with some answers to the above questions at your convenience.

Regards,

Jared A

[Dennis_Knutson]

Jared,

Here's a picture of the board. It's part number is 184411D-01. I think the part number of the working board is 184411E but right now it's inside a rack mount pc inside the only working version of a tester that I need to get working ASAP. I hope you can see that there is a void where the daughter board is - no ICs solder directly.

Thanks

Dennis

[JaredA]

Hello Dennis,

Are all three of your devices (the ones that are not working) like the one in the picture?

Could you please provide me with the serial number of all of the devices that appear this way? I am going to talk to the Multifunction DAQ Product Support Engineer about this issue. I will be back in touch with you.

Jared

[JaredA]

Dennis,

You should get in contact with a sales representative regarding this issue. (888) 280-7645. If that is the way the boards were received, we need to get you some replacement boards immediately. Our boards are tested before they are boxed up, but for some reason, thse daughter cards were removed after the testing stage and before they were boxed up to ship.

If you can provide me with the part number and serial number of all of those devicse, we will definitely look into how/why this occrued. Please let me know if there's anything else I can do for you in the mean time.

Jared A

[Dennis_Knutson]

Hi Jared,

The serial numbers are 104E54D, 104E555, and 104E558. I'm sending them back to Austin today under RMA #607427. At least now I know I wasn't going crazy when I couldn't get them to work.

Thanks

Dennis