SCXI 1001, SCXI-1102 and SCXI-1303 not working correctly with DAQmx

[ilabtech]

I have recently upgraded from Labview 6.5 to Labview 8.2 and now my SCXI 1001 with a SCXI 1102 and SCXI 1303 terminal block no longer reads the correct voltage.  Using the old version of labview thermocouple measurements are correct at 0.5mV; however using the new version of labview and DAQmx the thermocouples are reading 5V.  Everything is installed correctly as it still works with the older version of Labview, is there something that needs to be reset or change so that teh SCXI will function properly with DAQmx?

[Ima U]

Hello ilabtech,

From my understanding you are using an SCXI 1001 chassis with an SCXI 1102 and 1303 terminal block to perform thermocouple measurements.  You are upgrading to LabVIEW 8.2 and DAQmx.  I am assuming you were using LabVIEW 6.1 since there isn’t a LabVIEW 6.5.  You mentioned that are able to get a correct reading of 0.5 mV with LabVIEW 6.1 but you see a rail of 5V with LabVIEW 8.2 and DAQmx. 

My first suggestion is that you ensure that the SCXI is set at the appropriate range and for the correct thermocouple type.  You can also configure these settings in MAX as detailed on page 27 of the SCXI 1102 User Manual and Specifications Guide. 

My second suggestion is for you to start off using an example program to see if you see the same error.  When you are in a LabVIEW 8.2 VI you can go to Help>>Find Examples to open the NI Example Finder.  You then choose Hardware Input and Output>>DAQmx>>Analog Measurements>>Temperature>> Cont. Acq Thermocouple Samples-Int CLK.vi.   This example program is supported by your hardware and is a good resource to use to troubleshoot.

If these suggestions aren't helpful please answer the following questions in your reply.

1.        I would like to know what range you have set the SCXI 1102 to read. 

2.       What version of DAQmx are you using?  You can find the version my opening Measurement and Automation explorer (MAX), expanding the “Software “and clicking on NI-DAQmx.

3.       What operating system are you using?

4.  Does your Traditional DAQ program work in LabVIEW 8.2?

[ilabtech]

I have check your suggestions and the board is configured properly in MAX and the example program gives me the same error that I was experiencing with the test panels in MAX.  If I set the range from 0 to 50C labview reports 149C and it should be reporting ~24C.  If the range is set to 0 to 1000C (which is where I need to be) labview reports 1260C and it should still be ~24C.  (My reactor is off at the moment, but it typically runs at 850C). 

Operating System = XP with service pack2

NIDAQmx = 8.5.0f5

Labview = 8.2

MAX = 4.2.1.3001

The traditional labview program will not run in labview 8.2 as the legacy vi's used in the old version are no longer support/included with labview 8.2.  We are trying to update our code but cannot due to the measurement errors we are experiencing.

[Ima U]

Hello ilabtech,

You mentioned that the setup does work with Traditional DAQ and LabVIEW 6.1.  This shows that the hardware is not damaged.  I would like you to install Traditional DAQ on your LabVIEW 8.2 and test out your traditional DAQ code in LabVIEW 8.2.  You can go online and download Traditional DAQ version 7.4.4 and test your original code on LabVIEW 8.2.  This should help us to isolate the problem as the DAQmx code.

[ilabtech]

I have installed the legacy vi's and the original code that we used on our old computer loads, but it will not run.  We get a message saying it is communicating with the device, but that a configuration function is not supported.  It seems like the problem lies with a bad driver or setup file as all of the thermocouples that I am trying to read are nearly 5 volts when I use the MAX test panels.  Does this suggest that there is a problem with the new software?

[Ima U]

Hi ilabtech,

So far we have not been able to get your LabVIEW 8.2 to work with DAQmx.  We tried running a simple DAQmx program with your SCXI hardware and you received errors.  We also tried your Traditional DAQ code that works with your LabVIEW 6.1 setup and you receive errors.  I would like to narrow down what the problem is originating.  Is it LabVIEW 8.2, DAQmx 8.5 or the hardware?

Test LabVIEW 8.2

Let us test out your LabVIEW 8.2.  We can do this by running and example program to see if LabVIEW is functioning properly.

Open LabVIEW 8.2.  Choose “Find Examples” from the “Getting Started Menu”.  Choose Analyzing and Processing Signals>>Signal Processing>>Select Signal.vi.   Run this VI to ensure that your LabVIEW installation is functioning properly.

Test DAQmx 8.5of5

Open Measurement and Automation Explorer (MAX) and select My System>>Devices and Interfaces>>NI-DAQmx Devices.  Select your device and click “Test Panels”.  The Test Panels allow you to test out your device.  Take note if you experience unexpected behavior. 

Test the Hardware

Set up the exact same SCXI hardware that has been failing for you on DAQmx with your old LabVIEW 6.1 and Traditional DAQ and see if you can run your code.

[ilabtech]

Through phone tech support earlier this week we have solved this problem.  It was a hardware communication problem with the new computer.  Everything is working fine now.  Thank you for the help.