USB-6009 Temperature Acquisition

Hi All
I seem to have some brain fade today. I need to use the USB-6009 to with a J type thermocouple. When I hook it up the temperature is not correct and widely varies. I am getting reading from 0 to 60 C at room temperature. I need to incorporate this into another circuit for testing. I assume that I am overlooking the simple and obvious. I have tried using a DAQ Assistant and a DAQmx. Any help will be appreciated.
Thanks
Gerald

Hello Gerald,
You don't have a brain fade! I recently got in a few usb-6009's and am seeing a similar response when trying to measure temperature with thermocouples.
I don't believe this is noise as much as resolution on the usb-6009. At this point I have added resistors to bring down noise but am seeing the same "waver" that you describe (although not quite as extreme). I am looking into building a signal amplifier or alternatively purchasing a TAC80 thermocouple-to-analog converter for use with the usb-6009.
Have you had any progress with your issue?
Adzel

Similar Messages

Measuring temperature Via Thermocouple and USB-6009?

Hi,
I am trying to perform temperature measurements using a k type thermocouple and the USB-6009 DAQ. I tried to use the Cont Acq Thermocouple Sample.vi from LabVIEW's example list, but unfortunately I don't know how to fit my DAQ and thermocouple in the vi code. I don't know how to create a thermocouple temperature measurement channel or how to get all the channels in the task, etc.
Any help is appreciated.
Thanks.

bilbeigg,
It should be noted that the USB-6009 is not well suited for thermocouple measurements. It has 14 bits of precision with a minimum input range of +/-1V, which means it can only detect a voltage change as small as about 122 microvolts. This is much too large a change to get a good temperature reading with most types of thermocouples. Here is a discussion thread on the same topic (Note that the USB-6008 and 6009 are very similar):
http://forums.ni.com/ni/board/message?board.id=170&message.id=294080#M294080
Here is a knowledgebase that explains what you are seeing:
http://digital.ni.com/public.nsf/allkb/8166630BD6965EEA86256FDD0052E89C?OpenDocument
Chris M
Message Edited by CMal on 03-12-2008 12:17 PM

Usb 6009 acquisition fall after 15min

Hello,
Like it's said on the name of my post i have some problem with my new usb 6009. When i start it all work good but after a while my two AI fall to 0V. I put my code in joint pieces. I use AI0 and AI1 with a 220ohm resistance.
Thank you
Samuel Rioux
Attachments:
test.vi ‏30 KB

Hi skling,
DON'T use an additional Wait function when you have set your DAQmxRead to use a certain sample rate!
It will wait on it's own and after some time you will miss to read samples in time...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Usb-6009 high-speed continuous acquisition for slow control loop application

Hi,
After watching a few Youtube videos, I successfully built a control loop in LabVIEW using my USB-6009. Currently, this loop is limited by the speed my actuator can take and respond to commands, topping out at 200 Hz. This is completely sufficient for my application. My question is more regarding the wasted potential of the USB-6009 to acquire samples at a much higher rate than what would be obtained if I used a simple single sample-on-demand during every iteration of the loop.
It seems to me that having the USB-6009 continuously acquire samples and having my control loop periodically check in for the latest data when it is ready to execute would have the advantage of allowing me to average groups of samples together to lower the overall noise associated with the measurement process (I am reading voltages from an amplified photodiode).
1) Does anyone know how I would instruct the USB-6009 to continuously acquire at say 10 kHz, so that on each loop I will have 50 or so samples that can be averaged together for a more accurate measurement of my control variable? Unfortunately, I'm new to this and not too familiar with DAQmx Timing.vi.
2) I've heard that reading into a buffer can increase latency for moving data into the computer. Given the low speed of my control loop, I don't foresee this as being a problem. Is this a correct assumption? I can probably live with an extra millisecond of latency.
3) I goofed around briefly with DAQmx Timing and managed to see a buffer overflow error. Certain rare events will by necessity cause my control loop to take much longer to execute, so I cannot guarantee that occasionally during normal operation I will not overflow the buffer. Can I suppress this error so that the dialog box does not pop up and the program continues to run uninterrupted? If the buffer overflows and old data gets overwritten it isn't a big deal for me since the control loop is only concerned with the latest data anyway.
Thanks for any info!

Howdy Patrick!
Here is a picture of the front panel:
Here is the block diagram:
And I've attached a copy of the VI saved for LabVIEW 7.1.
Regards,
Barron
Applications Engineering
National Instruments
Attachments:
most recent samples.vi ‏73 KB

USB 6009 lock-ups?

Hello,
I'm having a strange problem with my newly aquired USB 6009. I've written an app to read the temperature from a temperature controller using the 6009 and that all works fine. However, the problem comes when I port this code into another application. The code is intended to run in a parallel loop to the main execution loop, to continuously read the temperature whilst other data is captured and process (all done in the main loop). Both applications run quite happily when separate. When I bring them together the applications sometimes, but not all the time, refuse to quit and just lock up. I have no idea what is happening as it is not a case of one loop remaining running (I've tried separate stop buttons) and they will run together quite happily. The problem only comes when I hit the button that terminates the main loop (this also triggers the other loop to stop - I'm sure this bit works as I've used the same method in another vi).
The main loop should, in theory, just close. The loop with the USB reads (using DAQmx Base) will stop and then clear the task (DAQmx Base Clear I think). Sometimes the DAQmx Base Clear runs and the program stops fine, other times it runs and the program locks, other times it locks as soon as I hit the quit button.
Any thoughts as I'm completely stumped on this one? Like I say, apart from the one button triggering both loops to terminate there is no link between the two loops.
My only thought is it could be a USB issue as the PC also has a USB keyboard and mouse. I know from my home experience, when for instance plugging in my camera, it can cause the USB to lock if, say, my USB modem is running.

See the thread
http://forums.ni.com/ni/board/message?board.id=250&message.id=13722
John Weeks
WaveMetrics, Inc.
Phone (503) 620-3001
Fax (503) 620-6754
www.wavemetrics.com

USB 6009 thermocouple noise

I'm using NI-DAQmx 7.5, Labview 7.0, and a USB-6009.
I'm trying to get a more accurate reading from my j-type thermocouple. It is now distorted with noise and jumps rapidly +/- 20 degrees around room temp without any heat being applied. When heat is applied, it climbs as it should but with the same variation. I haven't moved to the labview side of it yet, I'm still trying to get a usable reading in MAX. I have it wired as a differential input with a floating signal source. I've installed 10k ohm resistors for bias current return as instructed. Installing the resistors helped but still leaves me with the readings shown in the attached pic. I've also tried grounding my USB 6009 with no results. Please help. john
Attachments:
thermocouple reading.jpg ‏41 KB

Hi John,
What you are running into is a problem with the actual voltage resolution of your USB-6009. This device has 14-bits of resolution over a minimum range of +/- 1V. That means that the voltage resolution is (1 - (-1))V / (2^14) = 2V / (16384) = 122uV. While this is an excellent resolution for such a low cost USB device, you will still notice problems when trying to make a thermocouple measurement. The reason for that is that Thermocouples make a very small output voltage (see image below).
Common thermocouple types have the following response:
K type: 41 microVolts per degree Celsius
J type: 56 microVolts per degree Celsius
T type: 52 microVolts per degree Celsius
There are a few options for ways to get around this limitation.
Good: You could read the signal in as a voltage and then manually convert that voltage into a temperature. This would be the least accurate method, but it should allow you to average out your signal and then use the Convert Thermocouple Reading.vi to show the voltage as a temperature.
Better: If you want to keep using the USB-6009 to measure thermocouple, what you really need to do is first amplify your signal before you connect it with your device. This should increase your resolution of the thermocouple allowing you to get more accurate temperature specs. This will require some more complex programming to properly scale your measurements, but it will give you more accurate readings for relatively little cost.
Best: Opt for getting a USB device that is designed for taking temperature measurements such as the USB-9211A. This device would give you a voltage resolution of 160mV/2^24 = 9.54 nV! That's over 12500x the resolution of the USB-6009 that you currently have.
Hopefully the above information helps you better understand what is going on and why. If you have any other questions feel free to post them here.
Message Edited by Otis [DE] on 01-13-2006 11:37 AM
Message Edited by Otis [DE] on 01-13-2006 11:38 AM
Otis
Training and Certification
Product Support Engineer
National Instruments
Attachments:
761029-Thermocouple_Voltages.GIF ‏10 KB

USB-6009 digital input change detection

Hi,
I am trying to acquire digital signals from an ni usb-6009 device using daqmx on labview 8.0. I need to write the signals from a port of the device to an output file only when there is a change in the signals and I am not able to do this successfully. I created a digital task in MAX and was able to select acquisition mode as '1 sample (On Demand) ' only. Any other selection for acquisition mode would result in error 200077 with the following message -
Measurements: Requested value is not a supported value for this property.
Property: SampTimingType
You Have Requested: Sample Clock
You Can Select: On Demand
I selected '1 Sample (On Demand)' acquisition mode and was able to see the channel values on running it in MAX as I rotated a device connected to the usb-6009 device. As expected the hex values on MAX were showing up as FF,7F,3F,BF and this pattern was repeated everytime I provided the input by rotating the device.
Next, I created a simple vi to use the digital task I setup on MAX. I want to be able to record the signals only when there is a change in the digital pattern from the channels.That is when there is atransition from FF to 7F to 3F and so on, the vi should write to an output file and if no change happens, it should not write to file. To do this, I explored the Timing vi and tried using the 'Change detection' mode, but that produced the same error as above.
Can anyone please suggest a way to accomplish what I am trying to do ? Any guidance will be a hugely appreciated.
Thanks
~Sej

All of that effort with sample rates, timing, change detection, etc ciuld have been avoided if you had read the specs. As you finally found out, the device only supports sftware timed i/o and no change detection. You wll have to do your change detection in software this is done with a shift register/feedback loop.

USB-6009 Analog Waveform Output

I'm trying to create an analog waveform from a USB-6009 device through one of the analog output channels. However, through the DAQ Assistant, I can only select the 1 Sample (On Demand) setting. When I test the device, I can only push a constant voltage out. If anyone has any advice on how to create an analog voltage waveform using this device, I would like to know.

>I am only a novice at LabVIEW and data acquisition in general.
I don't use Labview (I write in C++) so I can't help you with that. I try to answer questions about C/C++ and general hardware questions.
>What did you mean by software-timed waveform generation?
That's where the software driving the device sends a sample to the DAQ device, waits for the prescribed time interval, then sends the next sample. So the timing of the waveform is driven by the software, using the computer's clock, instead of by the DAQ hardware. Software-timed is less reliable and has (often) lots more jitter because of competition for CPU resources.
>Does this mean that I cannot generate a waveform that is more than 150 Hz?
It's worse than that. It means you can't generate a waveform faster than 150/N Hz, where N is the number of samples (data points) that define the waveform.
John Weeks
WaveMetrics, Inc.
Phone (503) 620-3001
Fax (503) 620-6754
www.wavemetrics.com

Usb 6009 not recognized in simulink/matlab 2012b

i have matlab 2012b and when connect DAQ ni usb 6009 matlab recognize it but when i open simulink library and Data Acquisition Toolbox and when add analog input it belongs "winsound Michrophone...'
so any body can help me to simulink/matlab recognize usb 6009
thanks

Hello,
The Data Acquisition Toolbox that you are using is supported by MathWorks®. It is supported under the version of the software that you are using. Please contact The Mathworks, Inc. for further troubleshooting steps.
MATLAB® and Simulink® are registered trademarks of The MathWorks, Inc. All other trademarks are the property of their respective owners.
Wear
National Instruments
Product Support Engineer

Usb 6009 freeze

Hi all,
When using the USB 6009 interface for reading out two sensors (temperature and pressure, using the Voltage they generate) and sending signals to valves, my program keeps working.
But after a while the USB module crashes.
Most of the time both input and output don't seem to work anymore. I don't get any error, it just doesn't work anymore. When I pull out the USB device and insert it again in the USB port, it works again perfectly
FYI (It happened once or twice that the outputs still worked, but I got no input from the devices.)
Does anyone have similar problems or knows how to fix this?
Thank you in advance.
Regards,
Bart
Solved!
Go to Solution.

Here is the code.
Attachments:
Leakage_test_v1.1.vi ‏355 KB

USB 6009 DAQ to use in Simulink at External mode with DAQ toolbox

hi
Currently I am using usb 6009 daq board for data acquisition in using simulink. I have created a model with taking analog input from data acquisition toolbox. Then when i want to run in external mode and try to connet to target, the following error is coming up:
Could not execute target data map file 'untitled_rtwin_win32\untitled_targ_data_map' or it does not exist. Stop the target, delete the untitled executable, rebuild the code,and try again. Note that execution of external mode requires the build directory to be present...
How can I solve this problem? For your info, I am using 32-bit matlab, version: 2012a
For your info, a snapshot of the error is attached,
Any help would be appreciated Thanks
Attachments:
Untitled.jpg ‏130 KB

Hi Mahmudur,
what does MathWorks say about this error message?
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

USB-6009 analog input at certain voltage

i am using USB 6009
i want to use a certain voltage to activate something.
i want to activate a pop up vi inside a case structure at a voltage of 2.9V.
i want to de activate the case structure at a voltage of 0.13mV - 0.16mV . then the sub vi will close.
How to setup the DAQMX?
can provide any help ??
example will be good.
pls show where to find the icons. thank you

Hi Ace,
There are several examples from the LabVIEW Example Finder (Help»Find Examples...) that describe using limits. I searched "limits" in the Example Finder and found several examples that might help, such as Limit Testing Measurement.vi, Waveform Scalar Limit Comparison example.vi, and Limit Example.vi. In each, you would have to modify it to include data acquisition, but it shows how to take sampled data as you would get from data acquisition and perform a limit test. The Express VI that Jennifer O. suggested will probably be the easiest route, but there are other VIs that could suit your needs, as seen in the other examples.
As far as state machines, there is a template built into LabVIEW that can give you a starting point for creating your own state machine. Under the File»New... menu, you can choose the state machine template under VI»From Template»Frameworks»Design Patterns»Standard State Machine template.
Please let us know if you have any specific questions we can answer about configuring your data acquisition or about a specific VI. I hope this helps!
Regards,
Missy S.
Calibration Engineer
National Instruments

Opening & closing a solenoid valve using ni usb-6009

Hi,
I am very new to labview so any help would be apprciated.
I am using the ni usb-6009 as a power source for my solenoid valve. The valve is 12vdc but because the max output voltage for the ni usb-6009 is 5v i have designed and build an op-amp circuit which will amplify the voltage. I want to create a vi that will give a +5v digital output when a push button is pressed and 0v when the push button is off. What would be the most efficient way of doing this? Thank you.
Solved!
Go to Solution.

How much current does the solenoid draw? You say that you are powering the solenoid from the USB-6009 so just converting the voltage from 5V to 12V will not work - there is a current limit of 8.5mA on the 6009 which will not be enough to power the solenoid. You will need to use an external supply that can provide sufficient current to drive the coils of the solenoid and then use a transistor circuit to switch on the supply from the digital output of the 6009 (which can't draw more than 8.5mA).
Once you've got your circuit right, you can use MAX Test Panels, the Data Acquisition Express VIs or the DAQmx palette in LabVIEW to control the digital output. There are lots of examples in LabVIEW on how to do this
Certified LabVIEW Architect, Certified TestStand Developer
NI Days (and A&DF): 2010, 2011, 2013, 2014
NI Week: 2012, 2014
Knowledgeable in all things Giant Tetris and WebSockets

How do I set up a triggered analog output on a USB 6009?

Hi! I am very new to LabView and am working on the control portion of my senior ME design project. It is an anti-tip brake system for a bicycle. The goal is: When critical time to tip is reached (by reading values from a rear wheel normal force sensor, taking the derivative and calculating this critical time), my cheap DAQ USB-6009 device will put out an analog signal to a transistor, which will spin a DC motor (attached to a worm gear setup) for a certain length of time (...This will change a pivot location in the mechanical assembly which will decrease brake mechanical advantage).
I have been trying to work with LabView 8.5. I get bogged down in confusion when I try to use G-code and get unexplained errors in using Express VI's (they're rather black box-ish to me).
I think that all I need to do is set up an analog input channel, take derivatives and values and put them into a formula for critical time. Then if the result is a "True", I want to begin an analog out sequence for a certain period of time (to get the motor to the right position).
I would appreciate any help that I can get with this one.
Attachments:
ABScontrol1.JPG ‏43 KB

chowph,
You are
correct with your last statement about performing a comparison on your data.
1. Are there any error codes or messages in the
errors you are getting? Or if you have screenshots of the errors you could post
then that would work too. Knowing the
errors would help in understanding where to start.
2. In your previous
post did you have a chance to try the examples or Kent’s example code he
posted?
3. What were the results of those examples and
your experiment? Again screenshots would
work fine here.
Since you
new to LabVIEW make sure to take advantage of the online training material and
tutorials we have on ni.com. I have posted
a few that I think may be helpful.
Learn 10 Functions in
NI-DAQmx and Handle 80 Percent of Your Data Acquisition Applications
Complete Data Acquisition
Tutorial
How Can I Learn
LabVIEW?
I hope this helps!!
Message Edited by Ryan N. on 03-31-2008 11:52 AM
Ryan N
National Instruments
Application Engineer
ni.com/support

Setup Problem in Measure 2.0 with USB-6009

I purchased a USB-6009 for my laptop (running XP Pro), and installed the NiDAQmx vers. 7.5 that came with the unit. I opened NI explorer, and tested the unit in there (using Test Panel). It worked nicely there, though the indicator light on the DAQ board was blinking. I then added my copy of Measure to the computer, but when starting MS Excel, I get the error message "Measure unable to detect a valid installation of NI-DAQ. Please install NIDAQ before using Measure for Windows Data Acquisition Add-In."
Is there a step I missed? or is there something wrong with my applications?

Hello dlclough,
Measure 2.0 is a Legacy application that works only with our Traditional NI-DAQ Legacy driver, not NI-DAQmx which supports the USB-6009. The blinking light on the USB-6009 simply indicates that the device is receiving power. However, if you go to this section in the Readme file for NI-DAQmx 7.5, you can look at your numerous options for programming NI-DAQmx. You can also use VI Logger Lite which is installed with the driver for simple data logging applications.
Regards,
Laura

USB-6009 Temperature Acquisition

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