Thermocouple Measurements on TBX-68T with PCI-4351

I have set up Traditional NIDAQ Virtual Channels for 2 different thermocouples. In a simple program, I wire each channel to AI Sample Channel.vi and get the temperature reading. This works fine. However, when I do this inside of a larger code where I am also reading voltage measurements on my PCI-4351 (using 435xFast.vi which I downloaded), the first thermocouple I read is always giving an erroneous error. Do I have to reset the board in some way before I take the temperature readings?

I've got just a few questions for you:
1. Are you seeing a large negative value anywhere else other than when you run your particular vi as a subvi? Test panels in MAX? Other example programs?
2. Do you have the latest drivers for your application? NI-DMM 2.3.1? NI-DAQ 7.3.1? NI-435x 1.1?
3. Have you tried reseting the board in MAX and then running your application? If this takes care of that first bad sample, you could try calling Reset Device in the Traditional DAQ function palette before starting your acquisition.
Please let me know what you can. Have a great Thanksgiving!
Logan S.

Similar Messages

  • Measuring temperature with PCI-4351 & TC-2190

    Hi,
    I am a new LabView developer. I have a PCI-4351 data logger card and a TC-2190 thermocouple chassis. I cannot communicate with the 4351 cuz I don't know how. I've set up a channel with MAC and the hardware test works okay, but I can't find the right object to grab the measurement when I'm creating the vi. Do I use NI-DAQmx or VI Logger functions to take simple instantaneous temp. measurements?
    Is there some example code I can start with? I tried to run the ni_435x_thermocouple.vi example that I downloaded from the developer zone, but there are several sub-vi's not loaded on my machine (eg: AI Hardware Config.vi) that it tries to find upon launch. Looks like a vestiges of LabView 5 that aren't there anymore. Is there an easier way for this LabView 8 user?
    Sincerely,
    Jack Santori
    410-471-6262

    Hi Jack,
    The PCI-4351 only has support for the Traditional NI-DAQ functions and not NI-DAQmx.  It sounds like you don't currently have those drivers installed on the system, and this is why the Traditional NI-DAQ function AI Hardware Config.vi cannot be found.
    If you are running Windows 2000 or XP, the most current version of the Traditional DAQ drivers available for download is 7.4.1 and they can be downloaded here.  If you are not using one of these operating systems, Traditional DAQ driver versions for another OS can be found here.  Example programs are a great place to start, and the Developer Zone includes a wealth of information.  Installing the Traditional NI-DAQ drivers will also include example programs that you can open and run in LabVIEW 8.0 by going to Help>Find Examples.
    Regards,
    Andrew W
    National Instruments

  • Traditiona​l ni daq using tbx 68t with error 10685

    Hi im new, I have tried to create a program that will allow me to accept temp readings. i have a tbx 68t device and a pci 4351 card from which this is read.
    I have uploaded the vi.
    i keep getting a message of 10685 - the clock rate exceeds the boards recommended max. rate, even when i have the clock rate to a low 10.
    any help is much appreciated, i am fairly new to daq with labview. i do appolgise i have yet not annotated on the program.
    Thanks
    Notay
    Attachments:
    thermocouple example.vi ‏37 KB

    Hi again Notay,
    The 4351 Device has specific rates that you can sample at for single or multi-channel acquisition. There are six possible reading
    rates – 10, 50, and 60 readings/s in single-channel acquisition mode and 2.8, 8.8, and 9.7 total readings/s in multiple-channel acquisition mode.
    See the data sheet or manual linked bellow for more information.
    http://www.ni.com/pdf/products/us/2mhw296-297e.pdf
    http://digital.ni.com/manuals.nsf/websearch/924939​4DFC45FA3D86256FD20078D836
    Jon B
    Applications Engineer
    NI Uk & Ireland

  • Temperature Measurement using Iex Thermistor with PCI 6259

    Hello All,
    I am having some difficulty measuring temperature using MAX with Iex Thermistor setup, and would like to know if I have missed any thing important. I am using external current excited thermistor with 2 wire configuration and PCI 6259 card with MAX.
    This is a channel that was originally configured to Voltage measurement and MAX measures about 900mV from this channel OK, the voltage converts to Temperature to be around 30C. Then I added a new channel and configured it to measure temperature directly using MAX default Iex Thermistor setup. This is when the problem show up: I will get a constant -273C instead of 30C as expected when run the channel in MAX. I must have been doing something wrong here.
    Your help is greatly appreciated!
    Bryan
    Solved!
    Go to Solution.

    Hi Ravens, thank you for taking the time on this problem.  I am sure the issue was not caused by the A, B, C parameters being wrong, as when I ran the channel in MAX, I am getting a constant -273.15 value, and it was not updated as a real measurement.
    To your 2nd question, this is a case of measuring 1 thermistor value using the Iex Thermistor method vs. Voltage measurement.  If I set it up to measure Voltage directly, I can see the realtime updates of the measurement values of voltage, which converted to Temperature in my VI to be reasonable values of temperature.
    Bryan

  • TBX-68T temperature measurement errors

    I am using a TBX-68T with a PXI 4351 card to measure the temperature of a steel plate while the plate is undergoing a TIG (electric arc) welding process. To my knowledge (and based on past experience), the device is connected properly in MAX, with the TBX-68T selected as the accessory. In MAX it also passes the tests. Using the built in CJC and specifying a K-type thermocouple at a range of +/-0.625v, MAX reports temperatures of -80C. The temperature remains nearly the same as the range is increased, but if I change the range to +/-3.75v, the temperature suddenly jumps to 100+C. I used the Measure Thermocouple (with accessory).vi that comes with the driver, and it gives me the same readings. Furthermore, when I initiate the TIG welder the card reads extremely negative (-10e9) temperatures.
    What is odd, is that I have used these devices for the exact same process in the past and it generated believable results. 
    How can I fix the current temperature offset problem? Could I have possibly damaged the unit? Is it possible to use the TBX-68T to reliably detect temperature in arc welding process? 
    Thanks,
    William

    Hello,
    Becasue TIG welding creates a large electrical discharge I am concerned that you may have shorted the card.  What kind of isolation did you use to ensure a separation between the TIG process and the temperature measurement? Because the error is read by both your program and MAX it must be either the temperature configuration or the card.  Could you try to conduct a simple Voltage measurement with the 4351, lets say a AA battery.  You should be able to read 1.5-1.6V.  If this works than the card should be fine, (make sure to test all channels that are failing). 
    If you cannot read the proper voltage on the card, then it is possible that the card will need to be repaired. Please update us so we can help you further.
    Thank you 
    Regards,
    CharlesD
    Digital MultimetersSchedule a Free 1 Hour LabVIEW Tutorial with an NI Applications Engineer

  • TC measurements with PXI 4351 DAQ Card

    (I am using version 6i of LabVIEW). I am trying to create a VI that will use a PXI 4351 Card with a TBX-68T to take 4 thermocouple continuous measurements. I am also acquiring 8 voltages with a 6030E and TBX-68 and writing them to a file. My voltage data acquisition is modeled after "Buffered Continuous Analog Input.vi" I would like to aquire voltages and temperatures in the same vi, but using different devices and accessories. (I need a higher frequency for the voltage acquisition, and more precision with the temperatures). Is there a subvi I can use to collect the temperature data in the same vi as my voltage? I don't want the thermocouple DAQ to interfere with the voltage DAQ, either.
    I tried the NI435x thermocouple.vi
    but I couldn't get the Built-in Cold Junction Sensor to work or figure out how to combine it with my exisiting voltage acquisition. I also got NaN for my readings, and I checked the wire connections in all the sub vi's as suggested by another solution.
    Any comments would be great. Thanks in advance.

    Claudia-
    Thanks for the response.
    Regarding the CJC- When I switch it on, the temperature readings I get are very random, roughly negative 1 degrees. (I am operating right now at room temperature, and will be using J-type TC's to measure ~43 degrees C). Also, when I use the built-in CJC, the aquisition rate seems to slow down considerably. When I use the "user specified" everything seems to be ok, including the aquisition rate.
    I measured the resitance of the Thermistor on the TBX-68T and it was about 5000 Ohms, as expected.
    Just to make sure: When using the TBX-68T, do I need to hard-wire a thermocouple to Channel 1/auto-zero and another to channel 0/CJC? Because I connected a TC to channel 0 right now, but I wasn't 100%
    sure.
    I've attached my main vi and two sub vi's that I am using for the voltage aquisition part of my project. (Note:the current measurements are just voltage measurements multiplied by the recipricol of the resistance it was measured across, ie. 10).
    I would like to keep this file as is because it writes to a file exactly the way I want it to. I'd like to have the temperature aquisition with the 4351 in the same vi as the 6030E so that they both stop and start at the same time. I am just not sure how and where to log the temperature data since there will be fewer data points than the voltage data. Any suggestions? Should I write two separate files? can I somehow append them?
    Thanks again. Hope to here from you soon.
    Attachments:
    EBlackMainDAQ.vi ‏107 KB
    Save_Data8.vi ‏45 KB
    Build_String_Array5.vi ‏33 KB

  • PCI 4351 cjc with SCB-68

    Is it possible to enable cold junction compensation using a PCI 4351 board with a SCB-68 terminal block?
    I have searched around and tentatively concluded that it is not possible.  Under the "accessory" option in MAX SCB-68 is not an option, and TBX-68 does not have a checkbox for temperature compensation.

    Hello Craig,
    National Instruments recommends the following accessories that are designed to be used with the NI 435x for thermocouples/CJC: the cold-junction sensor is on analog channel 0 on the TC-2190, TBX-68T, and CB-68T accessories. Additionally, the NI TBX-68T (used with NI 435x devices only) is the correct acccesory which includes a built-in cold-junction compensation sensor and autozeroing circuitry (compared to TBX-68).
    Best regards,
    Ali M
    Applications Engineer
    National instruments

  • What device I have to connect with my PCI - 4351 to mesure a strain gauge signal?

    Hi,
    I have a PCI - 4351 with a TBX-68T messuring some termocouples signals, but I want to mesure a strain gauge too, what devices I have to connect my PCI - 4351 to make it possible?
    Thanks.
    Rafael.
    U.F.R.J.  Engineering student.
    Brazil.

    Q: what do i have to do to connect my devices to my jetpack??
    A: Jetpacks are wireless only devices.  You need to open up your computers wireless network list and select the network being broadcasted by the Jetpack.  Once you find the network then connect to it by entering the WiFi password provided on the back of the Jetpack.
    Q: what's the phone # for ???
    A: VZW is a phone company.  Every device that connects to the VZW network  has a phone number associated with it that allows it to dial in.  Although your Jetpack uses a phone number there is no need for you to have to enter or use it on anything other than for billing purposes.
    Q: it appears that my tablet has already picked up the jetpack as a connection. is that it ???
    Yes.  The Jetpack should be broadcasting some kind of unique network name.  The default network name (SSID)should be on a white sticker on the back of the Jetpack.
    Q: I have another device at a different location. how do I get that device connected to the jetpack ??
    A: Jetpacks have a very limited range.  You need to bring your devices within the wireless radius of the Jetpack in order for them to connect to it.   Normally a jetpack can only reach 1 room away from its current position, they are not as powerful as a normal home wireless router.

  • How to use external timebase for Two Edge Separation measurement with PCIe 6351

    Hi
    I am working with PCIe 6351 x series DAQ card.
    counter measurements.
    Here i need to measure the time/no edges between two edges. Falling to Raising of two signals.
    I got the measurement with internal time base.
    here i need to synchronize the measurements with external clock from the external setup.
    so i need to use that external clock,timebase for the counters.
    Any solution please..
    Regards,
    Hari

    First, the VI you mention is NOT for STC timer/counters. Therefore, it won't work.
    If you want to get the time interval between two edges, you want to use the Functions -> Data Acquisition -> Counter -> Count Events or Time VI. This will do the function you are looking for.
    Mark

  • How to measure frequency with PCI-4474 card

    Hi,
    I'm trying to measure frequency with PCI-4474 card.
    Any sample code available?
    Thanks.

    Hi,
    Thank you for posting the the NI forums.  There aren’t any example programs that ship with the DSA drivers.  Will you be using this with the Sound and Vibration Toolkit?  If so, there are numerous examples that install with this software package.  Check out the LabVIEW Example Finder >> Toolkits and Modules >> Sound and Vibration Toolkit. 
    In addition to this, you could also use the signal processing VIs that ship with LabVIEW.  There are also examples that ship with LabVIEW that use these VI in Example Finder >> Analyzing and Processing Signals FFT and Frequency Analysis.  There is an entire Signal Processing palette that should contain the functionality that you need.
    I hope this helps.  Post back if you have further questions. 
    Ed W.
    Applications Engineer
    National Instruments

  • Type C thermocouple measurement and compesation with DAQmx

    Need to make type C thermocouple measurment using DAQmx. Analog thermocouple channel configuration VI has spot for custom scales in the units box but nowhere to wire the scale. Want to use cold junction compensation so is the only option to use a voltage input then subtract the cold junction voltage and then run that value through a conversion formula?

    That does not work. The program seems to already try and apply a scale since I get an error from start task that says the prescaled units are already Deg C, and the scale of course goes from volts to degrees. When I try to change the custom scale name after start task I get an error that says the units are invalid for this measurement type. So there seems to be some coding that won't allow you to replace the scale for a thermocouple measurement. I'll probably have to take voltage readings and apply the scale after I subtract the junction value which is unfortunate I have to do things that way.

  • NI PCI 4351 errors

    I have a PCI 4351 thermocouple card and I am trying to use it under Windows XP. The following software was installed on the PC:
    Card driver: ni435x_v21 downloaded from National Instruments website
    NI-DAQ version 6.9.2f4
    NI-PAL version 1.5.5f0
    NI-VISA version 2.6.0
    Labview 6.1 full version
    Measurement an Automation Explorer that came with Labview 6.1
    The control panel of the PC shows the card correctly installed and working without conflicts. Measurement and Automation Explorer from NI detects the card too but the card fails the test. The error code 10401 informs me that this is an "unknown device". I tried it with another PC, now using the latest version of NI-DAQ, NI-VISA, and automation explorer but the result was the same
    QUESTION
    Is it safe to assume that the card is toast? (It was in a drawer for a while, so that is a possibility.)

    Hi nizkorod,
    Thanks for contacting National Instruments. I understand you are having a problem with your PCI 4351 board. Windows seems to be recognizing it, but the card does not pass the self-test in Measurement and Automation Explorer. This definitely appears to be a hardware problem since this is happening on two separate computers with different versions of NI-DAQ. The PCI-4351 should be working on both computers, with either NI-DAQ 6.9.2 or the latest 7.x. The board isn't completely toast though and can most likely be fixed. If you would like to get this board repaired then please give NI a call at 1-866-275-6964 and we can set up a repair.
    Have a great day!
    Erick D.
    NI Applications Engineer

  • Thermocouple Measurements using an RTD for CJC

    I am using an SCXI 1001 chassis with SCXI 1102 cards attached to TBX 1303 units and also SCXI 1121 cards attached to TBX 1328 units. I need to measure a number of K and T typre thermocouples in this system (using 1102 cards), and was hoping to use a PT100 RTD for my Cold Junction Compensation. Is it possible to achieve this by using the excitation current from an 1121 card and measuring the RTD value with the 1102 cards. It seems that when trying to select the CJC source in Max in the 1102 setup screen, there is no capacity for reading values from cards other than 1102 cards i.e I can't read the 1121 values.
    What is the best way to achieve this using the setup I have?

    James,
    On the virtual channels of SCXI 1102 MAX configuration if you have not set-up any additional channels at this point then the CJC selection will only offer the internal Thermistor for it's CJC reference or a user value defined one. If you wish to use a PT100 you will need to set this up in MAX first using the Virtual Channels. Once you have that working go back to the SCXI 1102 and configure the CJC reference as User Defined, you should then be able to use the PT100 channel that you have just created.
    Side note: The 1102 has been designed to thermocouple measurements and the internal CJC should be accurate enough for general measurements.
    Kind regards
    Joe
    NI-UK

  • NI 4350 S1/S2 Switches (TBX-68T)

    I'm using the TBX-68T terminal block with an old NI-4350 USB device for analog input from a pair of thermistors.  The TBX-68T has a pair of switches labeled "S1 S2", which are for the current source(s): (the 4350 has a 25uA source and the 4351 has an additional current source).
    My question is, how are these switched wired?.....(i.e. why do I need to throw both switches ON to get the 25uA current source on the 4350)?
     It works, but I may also have to use the 4351 and I want to know the details of how S1/S2 function.  Originally I thought S1 would be for the 25uA current source and S2 would be for the 2nd current source in the 4351, but I had to through both S1 & S2 to get the 25uA supply.  
    I've checked the online NI PDF documents for the 435x and 4351 and I've not been able to find this detail.

    Hello PointOnePa,
    I will look into this to see if I can find out why both switches have to be used to access the current excitation.  However I believe that on the 4351 you will still only be able to access one of the current excitation values.  Which ever excitation value you select in software will be available if S1 and S2 are switched on.  I do not believe there is a way to access both excitation levels at the same time.  I will do a bit of research and see if I can find any evidence to the contrary.
    Are you trying to access both excitation levels at the same time or just trying to figure out how to access the 1mA level externally?  If you just want to get the 1mA level then you just need to select this in software and turn S1 and S2 to on.
    Let me know what you're looking for and I'll let you know what I find.
    Cheers,
    Brooks

  • Data acquisition and frequency generation togather with PCI-6251 and LV8.2

    Hi friends,
    I am a new user of Labview. I am using LB8.2 with PCI-6251 .
    I have to generate frequency and then measure the data and then for next frequency and so on.
    i know that for this i have to use looping and that is not a problem. The real problem for measurement is to identify whether the frequency is been generated. if yes then measurements starts otherwise it should wait until it started. then after finishing the measurements send a signal to generator for changing the frequency and amplitude.
    Now these two things {generation and measurement} togather are not working correctly for me. so i make 2 diff file, one for generation and other for measurements <by modifying the examples>. I can run both file togather and it works. But it need lots off effort and time. I have to measure from 10Hz to 1000Hz in 2Hz frequency step and i cannt leave in between .
    can anyone help me how to syncronize these two togather .
    Trying to attatch. both the files here ..
    main_v1.1.vi --> for Measuring
    Oscilloscope.vi --> for waveform generation
    Attachments:
    main_v1.1.vi ‏150 KB
    Oscilloscope.vi ‏37 KB

    Hay thnx dude..
    I found the example and now it works
    once again thanks a lot

Maybe you are looking for