USB 6008 power up inconsistent

Hi,
Now that I have read enough about the DAQ 6008 and know that the DIOs power up to 5V when it is connected to the USB. And, knowing that , I have worked around it. But, here is my problem. very random behavior occurs in that few channels dont power up and I disconnect the DAQ and connect it back; they do. This random behavior is affecting my system. Should I trust the internal pull up or should I myself pull the voltage up to 5V using an external 4.7k resistor?
Thanks!
V
I may not be perfect, but I'm all I got!

Hi VeeJay,
I just looked through the USB-6008 user manual and specifications (found here) on page 23 it states:
At system startup and reset, the hardware sets all DIO lines to
high-impedance inputs. The DAQ device does not drive the signal high
or low. Each line has a weak pull-up resistor connected to it.
This means that the default power up start would have each of the digital lines set for input and pulled up to 5V internally. You shouldn't need an external pull up, though you can see on page 22 you can definitely add one.
My question is what ports are not at 5V when you plug the 6008 in the first time? Also, is it possible that some of the lines you have connected to the digital ports are driving the lines low? Do you notice this behavior when you don't have anything connected to the 6008?
Eric S.
AE Specialist | Global Support
National Instruments

Similar Messages

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

Low sample rate with NI USB-6008

Hello,
We are working on a project collecting data from a hybrid rocket motor for
University research. We are using a NI USB-6008, which has a sample rate of
10kHz. We are using 3 channels and getting a sample rate of ~60 samples per
second. I have attached the VI. Is this slowed by software, or physical
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.
Mark E.
Precision DC Product Support Engineer
National Instruments
Digital Multimeters (DMMs) and LCR Meters
Programmable Power Supplies and Source Measure Units

Laser operation with a USB 6008 DAQ

I'm wondering how I go about using the USB 6008 DAQ in conjuction with labView to turn on and off ths laser:
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.
I set this up and it didn't exactly work out as the laser was drawing to high a current and not working correctly.
Can anyone help me?

OK. The problem is that you need to supply about 30 mA to the laser to get it to work. The digital outputs of the USB-9008 are limited to 8.5 mA or less. Furthermore, a laser diode is a current operated device. If you apply a fixed voltage the current will vary depending on the exact doping used when the device was manufactured and on it instantaneous temperature. The curretn rises exponentially with voltage as in any diode. The link you posted does not have any real data about the electrical characteristics of that diode.
Typically a current regulating circuit is used to drive laser diodes. The simplest circuit is a resistor in series with the diode connected to a power supply with a voltage higher than 3 V. The value of the resistor depends on the power supply voltage, the voltage drop across thes witching transistor, and how much current you want to run through the diode. If you have applied 12 V to that laser from a source which can provide substantial current (>50 mA), you have probably destroyed it.
Lynn

PWM control through USB 6008/09

Hello all
I have already read a thread regarding the topic but i am not satisfied with the replies.
I have discovered few programs that can run PWM in LabView, but they all are for DAQmx. So, will those programs run through USB 6008? and i also read that the output will be a sort of slow response output?
I am aiming to power a micro-pump rated at 12VDC. So, i want to run the program in LabView, use the USB 6008 to connect to a the DC motor. I know that some amplification will be required because the output of the USB 6008 is rated as 0-5V.
But, my question is can i successfully control the speed of the DC micro-pump ( motor) using the USB 6008??
Regards
Nikhil
Many more kudos to give
Many more Kudos to give

Thanks for the reply.
If you just need to output voltages(not PWM) then you can use the Analog outputs of the 6008,
Analog Output
Analog outputs........................................2
Output resolution ....................................12 bits
Maximum update rate .............................150 Hz, software-timed
Output range ...........................................0 to +5 V
Output impedance...................................50 Ω
Output current drive................................5 mA
Power-on state ........................................0 V
Slew rate .................................................1 V/μs
Short circuit current ................................50 mA
Absolute accuracy (no load) ...................7 mV typical,
36.4 mV maximum at full scale
So yes you could output a voltage between 0 and 5 Volts. You could only change the voltage level every 10ms or so.
In answer to what your device (pump) requires I don't know.
"So, this got me thinking, do i really need PWM control for the micro-pump (DC motor)?"
Have you got a specification datasheet (website) of the pump? - I dont mind taking a look.
Have you looked in the NI Example Finder to VIs that generate PWM and AnalogOutput (AO?). In the example finder (help>>Find Example) it gives you information on what devices can use the examples - simply look for the ones which say usb6008.
Kind Regards
James Hillman
Applications Engineer 2008 to 2009 National Instruments UK & Ireland
Loughborough University UK - 2006 to 2011
Remember Kudos those who help!

Switching pneumatic solenoid valves using USB 6008

Hi,
I am a student working on a project in which I need to built a program to control/switch pneumatic solenoid valves to oporate on a pneumatic cylinder using the USB 6008 I am very new to LabView and DAQ.
The solenoid has two ports, one for extending the stroke arm of the pneumatic cylinder and the other for collapsing the stroke arm.as the solenoids works off of a 12V supply I have bulilt a darlington pair as a firing circuit for it.
I have had built different programs but I'm only able to send a signal to extend the stroke arm and then manually switch the wiring to collaps the stroke arm. So I have problem building a program that sends a signal to my circuit in such a way that ports of the solenoids go ON and OFF after a certain time.
I really appreciate your help
Elmira
Elmira

Dear Lynn,
Thanks for the replay.
I'm gonna try to best describe my system this time;
I'm trying to creat pitch motion using a pneumatic system including an air compressor, a solenoid valve and a cylinder.
The compressor is made by PowerFist and is capable of storing 5 gallons of air under a rated pressure of 125psi and can deliver 2.5cfm (cubic foot per meter) at 90 psi. The compressed air is sent directly to the solenoid valve. It operates using an electrical motor operating from a standard 110V power outlet.The cylinder has a stoke length of 19.7” and a bore size of 1.6” capable of operating under 130psi.
The solenoid valve used is 5-way 3-position. This means that there are five different ways the air flows inside the solenoid and the solenoid can set in three positions depending on the movement of the mechanical core inside. When air is transferred into the valve the mechanical core moves directing the air to the appropriate ports of the solenoid. The two outputs of the solenoid are sent directly to the pneumatic cylinder where extension and collapsing movements can be performed. the solenoid works off of a 12V supply so I'm using darlington pair transistor as the firing circuit .
Please see the attach for the pneumatic diagram.
Thank you
Elmira
Attachments:
pneumatic diagram.jpg ‏33 KB

Is the USB-6008 controllable by Mathcad?

Can I use Mathcad calculation power to manipolate analog data converted
by a USB-6008 interface?
If yes, please indicate examples sources (if any).
Thanks .

Hi nonnog,
I don't understand very well what you want to do, but you have 3 possibilities:
if you have Labview you can acquire data from NI device and then you can use MathCad via ActiveX with Labview with the specific libraries downloadable at link: http://venus.ni.com/stage/we/niepd_web_display.DISPLAY_EPD4?p_answer=&p_guid=B799BC00B8835510E034080...
if you haven't Labview, you can acquire and save data from NI-USB device with 2 NI software ("VI Logger Lite" or "NI Data Logger" provided at no charge with driver) and then you can read these files from MathCad
if MathCad provides the possibility to create Macro or to call dll you can directly use driver functions to acquire data from the NI-USB device.
I hope this helps you.
MarcoC

What amplifier will recomended for my k-type theromocoupler using usb 6008

I recently do a project about temperature control system using usb 6008, according to the spec, the minimum AI range is +/- 1V and the thermocouple giv the voltages in jz a mV, so what kind of amplifier will be recomamded? is there any amplifier chip set that available ?

Analog Devices AD594/AD595 Monolithic Thermocouple Amplifiers (Type J / Type K)
This would give you a conversion of 10mv per degree C using a single +5v supply you could get to a couple of hundred C
I get 11 bits of resolution available for the +/- 4v range (11 because I can't see a negative supply available so we are only using one side of the differential range).
That's a resolution of 2048 bits over 4v giving 0.001953 v per bit
The devices above give 10 mv per degree C so you would have about 0.2 C resolution and a maximum temperature of around 450 degrees C an minimum temperature of 0 degrees C.
The device draws about 1mW so you should have no problems with power consumption. (Hint Earth / Ground loops might be a problem).
I should add that whilst I have used this device many hundreds of times, I have never applied it to the USB 6008.
http://www.analog.com/en/prod/0%2C2877%2CAD594%2C00.html
Message Edited by Conseils on 05-08-2007 08:51 PM
Message Edited by Conseils on 05-08-2007 08:52 PM
Attachments:
46185785AD594_fbs.gif ‏17 KB

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).

Can I use more than one USB 6008 in the same program?

I am working on a project that may require up to six USB-6008 modules. Before I purchase more I need to know if I can use all six at a time in the same Lab View program. Can anyone help?
Solved!
Go to Solution.

Hello Nick,
LabVIEW is able to handel that number of DAQ tasks quite easily, however you must remember that USB has a maximum bandwidth. Therefore you would have to ensure that you have enough USB hubs on your PC. Typically there are between two to four USB slots per hub and each of these will have a maximum throughput rate which will divided between all devices attached to that hub. Therefore although you may have four USB DAQ devices attached to four USB ports if they are on the same hub you may notice greatly reduced rates of data transfer. What I would suggest rather than purchasing six or more USB 6008, why not purchase one PCI card which is able to handel many more inputs with a larger bandwidth.
Regards
Andrew George @ NI UK

How can i connect 24VDC to digital input (usb 6008)

hello,
how can i connect 24VDC to digital input (usb 6008), is it possible with some optocoupler?
thanks

The 6008 is a static DIO, so speed shouldn't be an issue. Therefore an optocoupler should work. Just make sure you get one the meets your specs.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
Unofficial Forum Rules and Guidelines

NI-DAQmx 8.3.0f0 installed but Found New Hardware Wizard shows up when plugging in a USB-6008

I have NI-DAQmx Device Driver 8.3.0f0 installed with LabVIEW 8.2 but when I plug in a NI USB-6008 I see the "Found New Hardware Wizard" in Windows XP. Since the DAQmx driver is installed shouldn't Windows recognize the device immediately?
I cancel the driver and I get the taskbar message "A problem occurred during hardware installation. Your device may not work properly."
The USB-6008 does not appear under Devices and Interfaces in MAX.
Help would be appreciated.
Thanks,
Dave

Ahh, I thought Windows performed an automatic search after cancel is clicked.
I clicked next and allowed Windows to search and it says:
"Cannot Start this Hardware"
There was a problem installing this hardware: USB-6008
The device cannot start. (Code 10)
I tried uninstalling and reinstalling the device but the results were the same.
Any ideas?

NI USB 6008: expected constant expression

I am using NI USB 6008 device. Looking at NI-DAQ\Examples\DAQmx ANSI C\Analog In\Measure Voltage\Acq-Int Clk\
So I want to modify the line that has
DAQmxErrChk (DAQmxReadAnalogF64(taskHandle,1000,10.0,DAQmx_Val_GroupByChannel,data,1000,&read,NULL));
as
    DAQmxErrChk (DAQmxReadAnalogF64(taskHandle,numsamps,TimeouT,DAQmx_Val_GroupByChannel,data,numsamps,&read,NULL));
where the corresponding variables have been defined before like:
Int_t xx=2;
const Int_t numsamps = const_cast<Int_t&>(xx);
    int32       error=0;
    TaskHandle taskHandle=0;
    int32       read;
    float64     data[numsamps];
    float64 RatE = float64(raTE);
    float64 TimeouT = float64(numsamps)/RatE;
But when I try to compile I get this error message:
$ nmake -f makefile.mak
Microsoft (R) Program Maintenance Utility Version 8.00.50727.42
Copyright (C) Microsoft Corporation. All rights reserved.
        cl -D_MT -D_DLL -MDd -EHsc -nologo -G5 -GR -MD -DWIN32 -DVISUAL_CPLUS
PLUS -D_WINDOWS -IC:\ROOT/include -O2 -c SNatInDAQ.cpp
cl : Command line warning D9025 : overriding '/MDd' with '/MD'
cl : Command line warning D9002 : ignoring unknown option '-G5'
SNatInDAQ.cpp
SNatInDAQ.cpp(261) : error C2057: expected constant expression
SNatInDAQ.cpp(261) : error C2466: cannot allocate an array of constant size 0
SNatInDAQ.cpp(261) : error C2133: 'data' : unknown size
NMAKE : fatal error U1077: '"c:\Program Files\Microsoft Visual Studio 8\VC\BIN\c
l.EXE"' : return code '0x2'
Stop.
What does it mean 'expected constant expression'? How can I get around this?
What I want to do is pass the size of that data array from another function.

Hi novaiscool,
I think the issue is that you are declaring numsamps as a constant and the DAQmxReadAnalogF64 function wnats a non constant parameter. Have you tried calling the function with a regular int or a value? Give that a try and see if you get the same error.
You will also need to initialize numsamps to something since you are allocating an array using that variable.
Give those things a try and let me know how it works.
Thank You,
Nick F.
Applications Engineer

Como controlar velocidad con un PID con USB 6008 ?????

Buenas tardes.
Acabo de adquirir mi placa USB 6008 y estoy comenzando a trabajar para poder controlar la velocidad de un motor trifásico asincrónico estandar.
Para esto contruí con un microcontrolador y una etapa de potencia la parte del variador. Y logré con esto que mi variador reciba una entrada de 0 a 5 Vcc y con ello varía la Frecuenci-Tensión de salida. Es decir solo necesito entregarle 0 a 5 V para que este actúe sobre todo el rango de frecuencias de salida.
También contruí una placa de aislación galvánica que separa absolutamente la salida analógica de mi USB 6008 con la placa del variador que construí, como para separar las masas y la señal y evitar inconvenientes en mi Notebook y placa de adquisición.
El feedback de velociodad lo hago con un sensor óptico y un disco dentado acoplado al eje del motor que me puede dar según mi necesidad 1 , 2 , 4 , 6 , 8 ó 10 pulsos por vuelta de acuedo a como lo ubique ó a mi necesidad.
Entiendo que la placa USB 6008 no es la mejor alternativa para trabajar a tiempo real, y mi sistema operativo ( windows vista x64) tampoco. Pero mi sistema es bastante inercial desde el punto de vista mecánico, y también lo es por la placa del variador que no tiene una respuesta instantanea por cuestiones de constantes de tiempo que le di al firmware del micro. Es decir que no necesito velocidad en el sistema ni en el VI que necesito desarrollar.
Resumiendo, necesito entrar a mi placa USB 6008 con pulsos ( los que se necesiten por cada vuelta del motor) y luego salir por una salida analógica ( de 0 a 5 V) con la información de velocidad que va al variador.
Tengo a mi disposición Labview 8.5 con el Control design & simulation que tiene incluidos subVI con PID's listos para usar.
En medio de este sitema, necesito generar un VI con el que pueda dar una referencia de velocidad desde un potenciómetro virtual en mi panel frontal, y que el PID en el programa de Labview corrija errores de velocidad por alguna pequeña variación de la carga, etc.
La verdad que estuve probando hacer un VI con un PID bastante simple, pero a la hora de simularlo, fuí modificando los parámetros del PID y no vi que se haga "mas inercial"cuando aumento el tiempo integral. Tambien probé salir de mi placa con una tensión analógica, y dar una referencia con un potenciómetro como para probar si el PID se hace mas "rápido ó lento" al modificar las variables Integrales ó derivativas y no vi variaciones en la respuesta.
Por eso es que pido ayuda en este foro, ya que probablemente alguien ya hizo alguna prueba, o me puede indicar como arrancar con este tema.
Este proyecto es solo con fines académicos, para mi tesis de Ing. Electrónica. Por ello el motor no tiene carga, solo el disco dentado y el sensor óptico, solo lo puedo frenar un poco para ver la corrección.
He comprobado que saliendo de mi placa 6008 con una señal analógica, pasandola por una placa que simula un retardo en el tiempo de esta señal, y reingresandola a una entrada de mi placa 6008 para luego con un VI generar el PID y tratar de que esta señal de entrada a la placa 6008 sea igual a la de setpoint, solo logro oscilaciones con una media que está lejos del valor del setpoint.
Espero que alguien me pueda indicar como empezar, ó darme algún ejemplo que me pueda ayudar, ya que no soy experto el Labview, solo acabo de empezar a usarlo.
Reitero que no necesito velocidad ya que mi sistema es lento, y solo debo variar mi salida analógica con velocidades muy bajas. Es decir no necesito respuesta inmediata.
La idea es hacer una demostración del uso de un PID en un sistema real con Labview.
Saludos...!!!!

Hola.
      Sigue unos links para su consulta.
     http://forums.ni.com/ni/board/message?board.id=240&message.id=8027&requireLogin=False
     http://zone.ni.com/devzone/cda/tut/p/id/3782
     http://zone.ni.com/devzone/cda/tut/p/id/6951
Saludos
Diogo.
Diogo Aparecido
Engenheiro de Aplicação
National Instruments Brasil

Using USB-6008 on LIS331 Accelerometer

Hi, I am looking to monitor my project with a LIS331 using the USB-6008 dac. Would this dac unit be acceptable with this accelerometer?

swong46,
I would recommend using a USB 63xx series DAQ device. You might also be interested in the USB 8452, which is a dedicated I2C and SPI device.
I can also put you in touch with some of our sales engineers, who would be the most knowledable about your options. Shoot me a PM if you're interested, and I can give you a number to call.
Kyle T.
Applications Engineering
National Instruments

USB 6008 power up inconsistent

Similar Messages

Maybe you are looking for