Reading an encoder with a USB 6008

Hello DAQmx users,
I have a USB 6008 and it doesn't work the way I want it to. I have done no troubleshooting or research and I refuse to give you any more information. You have 30 seconds to answer my question. i kid, i kid...
So here is my real question:
I have a USB 6008 that we use to do simple analog output. I'm looking for a way to use the USB 6008 to also get encoder information. I know that the USB 6008 cannot read an encoder directly, but I was wondering if anyone knew of or had any ideas of external hardware that could be used inbetween the 6008 and the encoder. I think it would be something like 1) the encoder generates pulses 2) external hardware takes encoder pulses, translates them into a digital value representing the angle and outputs this digital value 3) use the digital lines on the 6008 to read in the digital angle value from the external hardware 4) I don't lose my job.
I realize that this isn't an easy, optimal, or preferred solution, but I want to look into it before being forced to replace the USB 6008 with another piece of hardware.
Eric
DE For Life!

Oops.. Just realized that this got posted in the Motion Control Forums... Meant for it to go in the MIO forums. Sorry!
New thread is here, feel free to respond!
Message Edited by e-Cash-Money on 03-17-2006 04:30 PM
Eric
DE For Life!

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Reading simulated encoder with 6602

Hello!
I'm trying to read quadrature encoder (to be more specific this is an output of the pulse train generator that simulates the encoder).
In the attached picture you can see how the signal that i'm trying to read.
I need an advise about the correct filter settings.
Please also see the attached vi.
Usefull data:
Labview 8.2.1
Capturing device PXI-6602.
The Encoder is 16384 pulses. (If the reading is x4, i should get 2^16 - 65536 ticks).
The Encoder has differential outputs, but i've connected only A,B and Z.
The rotating speed is up to 5000 rpm. You can see in on the picture. (16384*(5000/60)=1,365,333MHz).
There is no problem to read the encoder with another devices, i have a motion analyzer from Control&Robotics solution and it works great.
Thank you.
Elman Izia.
001.jpg (78 kb)
Position capture.vi (171 kb)

Hi Elman,
The filter clock is used to make sure that your signal has
integrity and eliminates glitches. In
order for signal to be counted, it must remain high for two consecutive periods
of your filter clock. There are five
time bases (5us, 1us, 500ns, 100ns and programmed) that can be used as your
filter clock. The programmed clock can
be created by another counter and this setting will let a signal be counted if
it is at least twice times the filter period.
This is a great method to help eliminate errors that can be
introduced by noise, crosstalk or transmission line effects.
The TimebaseSrc property is going to select a clock to be
used as the source. In your example that
property is correct, you would want to use the 80MHz clock. The TimebaseRate property is going to be used
to divide the clock down to specific frequency.
It will divide the master clock down by an integer value and round it to
get a rate that is as close to the value entered. I would recommend leaving this number as
80MHz.
The MinPulseWidth property is going to determine the clock
of the filter clock. This property is
going to use the TimebaseRate property to create the predefined filter clock
settings. If your signal stays high for
two consecutive periods of the minimum pulse width, then it will be counted.
You need to determine the minimum pulse width that is
acceptable for your application. Since
your signal has a pulse width of about 360ns, you might want to use the
predefined filter clock of 100ns.
In short, you are creating a digital filter that will only allow
a signal to be recognized if it remains high for two consecutive pulses.
For further explanation, refer to the PCI/PXI–6602 User
Manual page 3-20.
http://www.ni.com/pdf/manuals/322137a.pdf
Respectfully,
Rob F
Test Engineer
Condition Measurements
National Instruments

Has anyone any experience with a USB-6008 and reading a thermistor value

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I am using 'BC Components' NTC Thermistor. I used the express VI to create a Vex input and entered the A,B,& C values from the datasheet. The thermistor is the 10K version and I placed a 10K resistor in series with it. I wired it as is shown in the connection diagram, and applied 2.5 volts to it.
I get completly the wrong temperature readings out of it! I called the NI help line in the UK and the engineer confirmed that I had done everything correctly but couldn't understand why it didn't work.
Any thoughts?
Steve Lawson

I had a similar problem, had it working at one point then screwed it up.
try this:
Attachments:
Temp Pressure EXpress.vi ‏92 KB

Drive higer load with the usb 6008

Hi all,
I need to drive a small motor with the analog output of the usb6008 device ... connecting it directly doesn't seem to work.
Any suggestions how get it working??? what does the 6008 output?
My motor works on a AAA battery dricetly.
Thanks a lot

On Apr 23, 12:40 am, lav21 <[email protected]> wrote:
> Hi all,
>  
> I need to drive a small motor with the analog output of the usb6008 device ... connecting it directly doesn't seem to work.
>  
> Any suggestions how get it working??? what does the 6008 output?
>  
> My motor works on a AAA battery dricetly.
>  
> Thanks a lot
The analog outputs of the USB-6008 are only rated at 5 Milliamps per
channel. One suggestion for getting it to work is to use an emitter
follower to get more current to drive your motor.
Howard

Low sample rate with NI USB-6008

Hello,
We are working on a project collecting data from a hybrid rocket motor for
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computer computation speed? This sample rate needs to be much higher. Any help
is greatly appreciated.
- Theo
Attachments:
Hybrid DAQ_10.vi ‏73 KB

Hi Rocket 154,
You’ve already had some
great responses, but I just wanted to add a little bit. A great starting point
to writing good code would be the Getting Started with NI-DAQmx: Main Page,
as well as the shipping examples (In LabVIEW, Help » Find Examples) already
mentioned.
If you navigate a bit
through the links (Basic Programming with NI-DAQmx » Getting Started with NI-DAQmx
Programming in LabVIEW) you’ll end up with some great resources. I recommend Learn
10 Functions in NI-DAQmx and Handle 80% of your Data Acquisition Applications.
It will detail many of the functions you can use and give you a feel for proper
code style in LabVIEW.
I hope that helps.
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Precision DC Product Support Engineer
National Instruments
Digital Multimeters (DMMs) and LCR Meters
Programmable Power Supplies and Source Measure Units

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http://www.maplin.co.uk/p/1mw-3v-red-laser-module-le07h
The laser must be turned on using 3V which isn't possible with this DAQ. I was thinking of usinga BC 109 transistor, then have the laser connected to an external power supply which is supplying 3V to the laser. then have the laser connected to the collector of the transistor.
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Can a USB Keyboard/Barcode reader be used with the USB port on the CRio

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Reading quad encoder with 9870

Hi there, my project involves using a quadrature encoder to sense the position and degrees of two encoders.
I have successfully modified the example vi from http://zone.ni.com/devzone/cda/tut/p/id/3921 using NI 9411.
However, I would like to know how I can read this data from the 9411 module into the NI 9870.
I have read examples of DMA from http://zone.ni.com/devzone/cda/tut/p/id/4534 but I do not clearly understand how it works.
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Thank you

Hi Elman,
The filter clock is used to make sure that your signal has
integrity and eliminates glitches. In
order for signal to be counted, it must remain high for two consecutive periods
of your filter clock. There are five
time bases (5us, 1us, 500ns, 100ns and programmed) that can be used as your
filter clock. The programmed clock can
be created by another counter and this setting will let a signal be counted if
it is at least twice times the filter period.
This is a great method to help eliminate errors that can be
introduced by noise, crosstalk or transmission line effects.
The TimebaseSrc property is going to select a clock to be
used as the source. In your example that
property is correct, you would want to use the 80MHz clock. The TimebaseRate property is going to be used
to divide the clock down to specific frequency.
It will divide the master clock down by an integer value and round it to
get a rate that is as close to the value entered. I would recommend leaving this number as
80MHz.
The MinPulseWidth property is going to determine the clock
of the filter clock. This property is
going to use the TimebaseRate property to create the predefined filter clock
settings. If your signal stays high for
two consecutive periods of the minimum pulse width, then it will be counted.
You need to determine the minimum pulse width that is
acceptable for your application. Since
your signal has a pulse width of about 360ns, you might want to use the
predefined filter clock of 100ns.
In short, you are creating a digital filter that will only allow
a signal to be recognized if it remains high for two consecutive pulses.
For further explanation, refer to the PCI/PXI–6602 User
Manual page 3-20.
http://www.ni.com/pdf/manuals/322137a.pdf
Respectfully,
Rob F
Test Engineer
Condition Measurements
National Instruments

Measurementproblems with NI USB-6008 in Visual C++ 6.0

Hi,
I'm trying to read some data from this device, but I'm sill in trouble
with it. With this code I get a few values, but then I get the
following error:
DAQmx Error: Attempted to read samples that are no longer available.
The requested sample was previously available, but has since been
overwritten.
Increasing the buffer size, reading the data more frequently, or
specifying a fixed number of samples to read instead of reading all
available samples might correct the problem.
Property: DAQmx_Read_RelativeTo
Corresponding Value: DAQmx_Val_CurrReadPos
Property: DAQmx_Read_Offset
Corresponding Value:
Task Name: _unnamedTask<0>
Status Code: -200279
Maybe someone could have a look in my sourcecode:
#define DAQmxErrChk(functionCall) if( DAQmxFailed(error=(functionCall)) ) goto Error; else
THardwareInterface::THardwareInterface(int dev)
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    sprintf(chan,"Dev%d/ai0:7",dev);
    float64     min = -10.0;
    float64     max = 10.0;
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    char        clockSource[] = "OnboardClock";
    uInt64      samplesPerChan = 1;
    float64     sampleRate = 1000;
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    DAQmxCreateAIVoltageChan(taskHandle, chan, "", DAQmx_Val_RSE, min, max, DAQmx_Val_Volts, NULL);
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sampleRate, DAQmx_Val_Rising, DAQmx_Val_ContSamps, samplesPerChan);
    DAQmxCfgInputBuffer(taskHandle,7);
    DAQmxStartTask(taskHandle);
unsigned short THardwareInterface::readValue(int kNr)
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    short        data[KANALANZAHL + 1];
    int32       pointsToRead = 1;
    int32       pointsRead;
    float64     timeout = 10.0;
    int32       totalRead = 0;
    unsigned short value;
    int32       error = 0;
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(DAQmxReadBinaryU16(taskHandle,pointsToRead,timeout,DAQmx_Val_GroupByScanNumber,data,KANALANZAHL,&pointsRead,NULL));
    value=(data[kNr-1]);
    return value >> 5;
Error:
    if( DAQmxFailed(error) ) {
        DAQmxGetExtendedErrorInfo(errBuff,2048);
        DAQmxClearTask(taskHandle);
    return -1;
Thanks, SWT

And here the sourcecode:
// cpp Datein zur Headerdatei THardwareInterface.h
#include "THardwareInterface.h"
#include <time.h>
#include <iostream>
#include <stdlib.h>
#include <string>
#include <NIDAQmx.h>
using namespace std;
THardwareInterface& THardwareInterface::exemplar(int dev)
    static THardwareInterface instanz(dev);
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THardwareInterface::THardwareInterface(int dev)
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    taskHandle = 0;
    char        chan[10];
    sprintf(chan,"Dev%d/ai0:7",dev);
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    float64     max = 10.0;
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    ausdatei.close();
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    int32            pointsToRead = 1;
    int32            pointsRead;
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    fehlerZaehler = 0;
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Error:
    if( DAQmxFailed(error) ) {
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        ausdatei <<
sysTime->wDay << "." << sysTime->wMonth << "."
<< sysTime->wYear << " "
     << sysTime->wHour << ":"
<< sysTime->wMinute << ":" << sysTime->wSecond
<< endl;
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        ausdatei << "DAQmx Error: "
<< errBuff << endl << endl << endl;
    if (fehlerZaehler <= 5)
        return liesWerte();
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    unsigned short    wert;
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Amplifying Type K Thermocouple for high temp reading with USB 6008

I am attempting to amplify a type K thermocouple so that the signal can be read somewhat accurately by a USB-6008. I have looked at the AD595 chip but it states a maximum useful temperature of 100 C and I am going to need to be reading up to 700 C.
Is there another amplifier chip that would work up to this temperature, or should I resign myself to using the signal unamplified and getting a very inaccurate (~30 C/division) reading for temperature?
Solved!
Go to Solution.

A heads up- some people have ran into issues using the chip with the USB-600x devices, various solutions. You may want to browse of these posts ahead of time:
http://forums.ni.com/ni/search?board_id=170&submitted=true&q=AD595
-AK2DM
~~~~~~~~~~~~~~~~~~~~~~~~~~
"It’s the questions that drive us.”
~~~~~~~~~~~~~~~~~~~~~~~~~~

Does USB-6008 student kit come with a LabVIEW 2009 textbook?

Hello.
I'm taking a LabVIEW class that requires the "LabVIEW 2009 Student Edition" textbook and software on DVD. I want to also get the USB-6008 Module, too.
Browsing the NI Academic Starter Kits, I came across the USB-6008 Student Kit, which says comes with the USB-6008 Module, LabVIEW Student Edition software, and SignalExpress LE. This Kit seems like the best package for me to purchase, but the website is not clear as to whether the textbook is included. Does anyone know if the book is included with the USB-6008 Student Kit?
Thanks,

Hi YTrunner,
Thank you for contacting National Instruments. I can confirmthat the 6008 starter kit does not come with the textbook. You would need to purchase these products separately.
Many thanks,
Andrew McLennan
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National Instruments

Error -10401 occurred at AI Group Config - in relation to USB-6008

I'm attempting to run a simple vi that uses AI Aquire Waveforms.vi to input voltage data that I have coming in from the USB-6008 DAQ. However, when I try running the program, I receive the error:
Error -10401 occurred at AI Group Config
Possible reason(s):
NI-DAQ LV: The specified device is not a National Instruments product, the driver does not support the device (for example, the driver was released before the device was supported), or the device has not been configured using the Measurement & Automation Explorer.
And I'm not sure how to fix it. In MAX, the device seems to be working properly and everyhting seems to work fine in the test panel, so I'm slightly at a loss. I'm running Labview 7.1, and installed NI-DAQmx 7.5 which came with the USB-6008.

Never mind. I'm new to Labview, and didn't realize that I could not use the traditonal Data Aquisition components with the USB-5008 (I didn't even realize that NI-Daqmx was different).

Will USB-6008 DAQ be able to power and record voltage for UMS T5 tensiometer at the same time?

I would like to use my NI USB-6008 to provide power to my UMS T5 tensiometer (http://www.ums-muc.de/en/products/tensiometer/t5.html) as well as take readings from it, but I don't know if this is possible to do properly. The supply voltage for the instrument can be as low as 5V, which I can easily get from the dedicated +5V channel. I am able to power the instrument and connect it to an analog input on the 6008 and measure a voltage in differential mode. However, while reading the support literature for the instrument, I find the following:
"Potential data acquisition pitfalls: Because the pressure transducer is configured in a Wheatstone full bridge, the input voltage and signal mV output cannot be connected to the same reference (ground). Hence, the signal mV output can only be measured using a differential voltage measurement. Therefore, do not attempt to make a single-ended measurement of the pressure transducer mV output." (http://www.decagon.com/assets/Uploads/MeasuringUMSTensiometerswithnon-UMSControlandDataAcquisitionSystems.pdf)
My understanding is that the 6008 can take a differential measurement if I attach the signal "+" and signal "-" to the positive and negative analog input terminals. However, it seems that all of the Ground ports on the 6008 are grounded to the same reference, which would make my voltage measurement invalid according to the paragraph above. So my real questions is: if I attempt to record the voltage using one of the analog inputs on the 6008 in this way, is the measurement valid? Or do I need to find a separate power supply with a different reference ground to ensure that the measurement is accurate?

The specification sheet for that device is very poor. The manual is not much better. Companies which want to sell scientific equipment should publish decent data sheets or get out of business.
In section 3.4.3 General requirements the device is described as a "non-amplified bridge circuit." This information along with the bridge impedance should be in the specifications because it is essential to applying the device under any circumstances other than the nominal behavior at 10.6 V.
The answer to your question is this:
You can use it with the USB-6008. The 5 V power supply will result in output voltages slightly less than half (5/10.6) the voltages specified under nominal conditions. You can use the differential input mode on the USB-6008. The absolute input voltages will be about 2.5 V with the 5 V supply. That voltage is within the working range of the device. The differences will probably be less than 100 mV. The resolution of the USB-6008 on the +/-1 V range is about 0.5 mV so your pressure resolution will be around 1 % of full scale. The input impedance and termination voltage of the USB-6008 will introduce some errors. These may be on the order of 5-10%. I cannot predict much better without the missing bridge impedance specification. Those errors should be systematic and relatively constant. A calibration of the whole system - sensor and DAQ device together should allow you to compensate for much of that error.
Lynn

Usb 6008 daq spi lcd server client

Hi.
I'm new to the labview.ich have a project and comes to data acquisition and remote monitoring
detaille:
2 computer are labview installed on both and connected to wifi / internet.
the server computer connected with ni usb 6008 and it pt100 temperature sensor
it should also include the measurement data display on an LCD
it should be the client computer also read out the measured values
has anyone an idea how could you start?., I will be very grateful

This sounds like a pretty big task for someone new to LabVIEW.
First get the DAQ working on the server PC. There are tons of examples that ship with LabVIEW for taking DAQ, go to Help >> Find Examples.
Getting the information to your other PC can be done many different ways, but maybe the easiest is to just use a Web Server to control the front panel.
http://zone.ni.com/reference/en-XX/help/371361H-01/lvconcepts/viewing_fp_remote/
Also you could remote into this PC using remote contol software and remote desktop.
As for displaying data on an LCD. A relativly simple solution is to use an Arduino UNO, the LIFA toolkit and an LCD connected to it. It is a little bit if a round about solution but the LIFA toolkit comes with code to output to LCDs connected and it is relatively easy to use.
EDIT: LIFA https://decibel.ni.com/content/groups/labview-interface-for-arduino
Unofficial Forum Rules and Guidelines - Hooovahh - LabVIEW Overlord
If 10 out of 10 experts in any field say something is bad, you should probably take their opinion seriously.

Acer pda n30 ni usb-6008

Hi! I want to connect Pocket PC Acer PDA n30 with NI USB-6008 card and with accelerometer ADXL311. Did anyone do somything symilar to this? Could anyone send me a link to a paper that has something to do with my question? I am looking for someone who has already measured movements of some parts of a human body with the hardware I mantioned. I need links to some papers. I'll be greatfull if anyone can help me.

PDAberlin:
I hope all is well. With the LabVIEW PDA Module, you can most definitely develop applications that run on your Pocket PC. There are some examples that you can use to get an idea on how to develop data acquisition applications for your Pocket PC device. They are located at:
C:\Program Files\National Instruments\"LabVIEW version"\examples\daqmxbase
C:\Program Files\National Instruments\NI-DAQmx Base\Examples
I hope this helps and feel free to post again if you need additional information.
Best Regards,
Rudi N.

Reading an encoder with a USB 6008

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