NEITHER USB-6008 can measure an AC voltage

Similar Questions

• NEITHER USB-6008 connect to thermocuples and pressure sensors, control valve

  I am endevoring to build a gasification plant biomass for bench scale test process control plans. NEITHER USB-6008/6009 will be adapted for use as a data acquisition. I'll take RTDS, thermocouples and pressure sensors. I don't want to use industrial automation controllers.  It is also possible to use the channel of analog output for sending signals to a control valve position (using sufficient current/voltage between the two drivers).

  (1) OK.  I just wanted to be sure that you were aware of the potential dangers.

  (2) an RTD is a resistance that has small changes in resistance per degree of temperature change. To measure that you have need of a current source and a sufficient resolution in order to detect small changes.  At 25 degrees C a typical RTD is 109,73 ohms and resistance ohms 0.38 per degree changes.  If you had 1 my crossing this RTD voltage through it would be 109,7 mV and the voltage change of 0.38 mV by degree.

  The resolution of the 6008 on the most sensitive range is 0.49 mV > 1 degree.  The accuracy of the 6008 is 1.5 mV typical.

  For a Type K thermocouple, voltage at 25 degrees is 1.407 mV and change by degree is 39 µV.  Millivolt solving half of the 6008 translates into about 12 degrees.

  If you need a source of excitement for RTD and a kind of amplification for thermocouples and RTD before she would make any sense to try to use USB-6008.

  (3) I have not used anything except LabVIEW with DAQ devices and drivers.  I think DAQmx can be used with MATLAB and other languages.

  (4) the 6008 is the low range made by NOR. You will need to go to a more expensive camera or add signals conditioning circuits.  Talk to your representative OR assistance in the choice of a suitable device.

  Lynn

• NEITHER USB 6008 voltage offset using CSR and measurement of diff.

  Hi all

  I am currently trying the NI USB 6008 housing and I'm getting problems when reading voltage analog using CSR or differential.

  So basically, what I want to measure is a PWM signal (0 to 12V), which is divided by a divisor of tension (by two). But instead of measured 0V and 6V

  I am in a position a constant 0.8V and approximately 3V.

  On the side of digital data acquisition, I give you on impulses for the SSR... and it works fine.

  I connect it that way: http://digital.ni.com/public.nsf/allkb/95CC0CB11D7DF3D18625712E000C4ABD?OpenDocument

  Would apreciate any help

  Best regards

  EDIT: Attached graphics acquired are

  What is the impedance of your voltage divider?  The input of the USB-6008 impedance is not very high. If the impedance of the partition is large, it could cause the effect you see.

  Lynn

• USB 6008 angle measurement?

  Hello friends

  I need to measure the angle of rotation of the shaft with a precision of 1 degree... is there any simple device can I connect with usb 6008 custom angle...

  Thank you

  180 degrees is very different from continuous rotation. Just wire a potentiometer to one of the analog inputs and try to calibrate it.

  You don't need the LM317.  It will not help you with what you have described so far.

  Lynn

• NEITHER USB 6008 tension problem reading

  Hello

  I am trying to program a USB-6008 on a mac. When I connect to the input to analog 5V output I get a reading of 3.67volts, while on an osscilascope, I read a 5volts voltage. Is this normal? Need to load resistors? Also, I get the same effect with the release of tensions for the analog output.

  Hi Zepp2,

  Thanks for your post. The pins are you connect together on your device? Depending on the type of connection you have the wiring may not be quite right.

  I found a few documents online which hopefully should help you:

  Field of connection for analog signals: http://zone.ni.com/devzone/cda/tut/p/id/3344

  USB-6008/6009 Getting incorrect voltage reading: http://digital.ni.com/public.nsf/allkb/95CC0CB11D7DF3D18625712E000C4ABD?OpenDocument

  Input analog USB-6008/6009 reads about - 1.4V Offset: http://digital.ni.com/public.nsf/websearch/E687933C5694AB00862570BD00593CA3?OpenDocument

  Please let me know if one of them will help out you.

  Kind regards

• NEITHER USB-6008 outputs in series to generate 10 V

  We wonder if it is possible to connect the AO0 the AO1 as a series voltage source that generates 5 + 5 Volts?

  The datasheet is not say, do or not, but he says they are independent.

  Worst case being short, one of the outputs short-circuit if the ground is common?

  http://forums.NI.com/T5/Multifunction-DAQ/how-to-combine-two-analog-output-voltage-from-USB-6008/TD-...

• NEITHER USB 6008

  Dear all!

  I'm looking for help on the NI USB-6008 case. I'm putting in place 4 K thermocouples using this USB-6008 4-channels. I made an express VI in the Labview 8.5 and I have installed all these 4 channels in this VI. The VI is attached for your review!  Come to the problem! I get strange readings of these 4 channels even if I have no thermocouple connected to the terminals with respect to this USB-6008. Please help me and explain what is happening? Why am I getting these strange temperature readings while there is no connected thermocouple?

  Greetings to all!

  Tajim

  Dear all,

  I'm sorry for not attaching the screenshot of this configuration! Here, it's this time!

  Kind regards!

  Tajim

• NEITHER USB-6008 and Linux Comedi compatibility

  Hello!

  Could you tell if NI USB-6008 compatible with:

  -Driver Linux Comedi

  - NI DaqMx Base

  If it is compatible, please give me the link for documentation on installing and programming.

  Thanks in advance,

  Vadim.

  Hi Vadim,

  What version of DAQmx Base you trying to install?  I recommend you to install NI-VISA first, version 4.5, here.  Please let me know if this does not work!

• NEITHER USB 6008 OEM DEATH

  Hello

  I have a problem with some NI USB 6008 OEM.

  They do not work! I have attached to my PC and the light starts flashing, Windows detects new hardware and everything's fine (the same way it usually works with the regular OEM-NIUSB6008 Board, not).

  Suddunly led turns OFF, and the jury never come back to life again. I run the MeasurementStudio, and I see the boards with a red cross or without serial number (when they are shown as if they were present in the system).

  I bought 10 boards and I don't want to try with anyone, because I don't know what is happening and I don't want to kill them all :-(

  We have developed some equipment with regular tips and there is no problem... What is the mystery with the OEM ones?

  Help, please.

  Thank you!!

  Hi Luciano,

  Thanks for your response and documentation on the flashing led behavior. It helped me a lot to know that if the led is flashing, it could be because it is not properly initialized.

  In fact, I had the 8.1 DAQmx version installed on my PC that worked perfectly well with regular advice to the NI USB-6008 (boxed version).

  When I plugged the OEM boards, the system seemed to load the drivers and then a message pops up saying "your device is ready to use", but as you know when I opened MAX he didn't have a serial number, or sometimes, he appeared with a red cross.

  So, I downloaded a newer driver: DAQmx 8.8. ... I installed it on my PC (first remove DAQmx8.1) and it worked

  So, the problem is solved! The problem was, I think, because of the bad initialization of the device. The problem is solved by installing a DAQmx 8.8 version. It works very well with regular and USB-6008 OEM boards.

• How properly using USB 6251 to measure the DC voltage

  Hi all

  I have a problem as in the http://forums.ni.com/ni/board/message?board.id=170&message.id=404676&query.id=250408section.

  I'm sorry for the repetition of the subject, but I read all your advice and have not yet solved the problem.

  My task very simply: I use USB-6251, differential mode to measure battery voltage Energizer 1.5V. But result shows > 10V? Mean.VI shows greater 4V (see attached photo)

  I do not understand what happed with my task?

  Please help me!

  Thank you very much!

  MC

  Hello

  Please post on the Forums OR!

  How do you have your battery connected? Do you use polarization resistors? This could be a grounding problem and can be fixed if the polarization resistors are used. See table 1 in this document , and the differential configuration for a floating source.

• How to properly connect USB-6251 to measure the DC voltage

  Hi all

  I have a problem as in the http://forums.ni.com/ni/board/message?board.id=170&message.id=404676&query.id=250408section.

  I'm sorry for the repetition of the subject, but I read all your advice and have not yet solved the problem.

  My task very simply: I use USB-6251, differential mode to measure the voltage of the battery (Energizer) 1, 5V (I connect AI0 pole positive and AI8 to the negative pole). But result shows > 10V and Mean.vi shows greater 4V (see attached photo).

  I do not understand what happed with my task?

  Please help me!

  Thank you very much!

  MC

  You have a floating signal source. Have you connected resistances to remove polarisation currents? Look at Table 1 at this link and make sure that you connect the wires in this way:

  Wiring and considerations of noise for analog signals

  You mention that you use differential channel AI0 again I can see that you measure AI4 on your façade. Have you tested the Max connection? Are what kind of reading you there? Don't forget to select the continuous Acquisition and acquire 100 samples to 1000 Hz. display a snapshot of the reading you get there.

• NEITHER USB 6008 AI acquisition and generation of pulse

  Dear users of LabVIEW,

  Greetings for everyone. I am a beginner of LabVIEW and I have a problem that I solved partially. I would really appreciate your help and suggestions that I searched for days without a bit of luck. The problem is as follows:

  I am the acquisition of tension HAVE (continue) 4 to 8 accelerometers. In the meantime, I send you a digital output signal each time when you click on the sampling frequency (i.e. 1000, 2000, 3000,...) If the sampling rate is 1000). In other words, try to send a signal of output digital (at a frequency n Hz) at intervals of 1 second (depending on the material). To make the digital output signal begins to blink a LED every one second. In addition, I need to write signals (voltage) AI and the LED blink timestamps PC (software) separately. All stages of the above are followed in my .vi program, but the real hardware/software level operations kill my timestamps. In other words each LED flash timestamps are not accurate, when I use LabVIEW measurement file express VI (the difference is not at least to the third decimal). In addition, the timestamp is kinda OK when I disable the file LVM write VI. Onemore thing I've noticed is that physically the LED blinks every second two times, I feel it's because of the shift register and loop delay of a second. Is there a way to control the speed of blinking (i.e. Boolean State must change to every 500ms without delaying the inside while loop).

  Results and comments:

  LabVIEW 2011 .vi, timestamp of files with or without generator of LVM (express VI) files are all attached. Please note that there is a considerable amount of drift in the consecutive timestamps when the file LVM generator is used, on the other hand there are derivative of 0.001 ms when the file LVM generator does not. The reason for horodateurs PC have is about aligning the various measures or observations or events to global time scale.

  Please give me any suggestions or help me do at least accurate to milliseconds in VI of witten. Finally, is there any USB DAQ module relatively inexpensive which allows to send an impulse to directly from channel impulse of output digital channels when the "n" sampling frequency Hz is obtained by level of material which could all be accurate, so that the software timer is completely reduced to a minimum. Although there are very material sophistiated of NOR, but our goal of this project is to build and test the system profitable.

  Thank you and I really appreciate your time and effort inavluable. Have a great weekend!

  Just change the samples to the constant playback at the entrance of the DAQmx Read.vi from 1000 to 500.

  Lynn

• NEITHER USB 6008 help to order 3 relays.

  Hello! I have a DAQ 6008, and I need to control the three relays for the filming of lights, so I scored a VI to activate the relay through three buttons. My problem is that I don't really know what kind of relay that I need. I need something like 5VDC to 230VAC. What do you recommend?

  You will need a driver-relay or transistor to provide current to fly this relay.

  On a datasheet for the relay, tried google?  The part number printed on the side of the relay.

  The ULN2003A is a good relay driver.  A 2N4400 transistor will do the job too.  Both are very easy to connect.

• USB 6008 weird analog voltage reading

  Hello

  I use the USB-6008 to measure a voltage of a Lithium battery, 3.66V.

  the battery come with a blocking diode (in series with the battery) of 1N5820, who have a fall of voltage drop of 0, 1V.

  battery with diodes in series (this is the way in which the battery is shipped with)

  -measure with DDM yield 3.66V without you connect to usb6008

  -measure with DDM yield connected to usb6008 (putting OUT VOLTAGE USB6008) 3.59V

  -able with USB-6008 performance 3.59V connected to usb6008

  battery with diode removed

  -measure with DDM yield 3.66V without you connect to usb6008

  -measure with DDM yield connected to usb6008 (putting OUT VOLTAGE USB6008) 3.66V

  -able with USB-6008 performance 3.66V connected to usb6008

  Thus, it seems that the problem is in the led in the series.  This is why the battery voltage has fallen to 0.07V? the series diode will hurt the USB-6008?

  Maybe people who know the circuits inside the USB-6008 can give me an answer.

  Thanks in advance.

  Hi learnerd,.

  The fall that you see is falling forward in the diode.  As an entry class device, the USB-6008 case has a relatively low input impedance (144kOhm) and thus draws a little current of the device.  Looking at the datasheet of the 1N5820 (http://www.onsemi.com/pub_link/Collateral/1N5820-D.PDF), Figure 7 shows that at 25 ° C, a draw of 50mA will cause a fall front of 200mV.  While the figure does not extend the curve below 50mA, extrapolating the given curve would indicate that a drop of 70mV would cause only a few current microamperes.

  A DMM will have a much greater input impedance (GOhms instead of kohm) and won't draw enough current to influence the measure, that's why you wouldn't see the decline with only the DMM.

  The diode will not harm the USB-6008 somehow.

  Good luck with your application,

  The f

• DAQ USB-6008 will be able to power and record voltage for UMS T5 blood pressure at the same time?

  I would use my NI USB-6008 to power my blood pressure monitor UMS T5 (http://www.ums-muc.de/en/products/tensiometer/t5.html) but also to take readings of it, but I don't know if it's possible to do it properly. The power supply for the instrument can be as low as 5V, I can easily get the dedicated + 5V channel. I'm able to feed the instrument and connect it to an analog input on the 6008 and measure a voltage in differential mode. However, when you read the documentation of support for the instrument, I find the following:

  "Potential pitfalls of data acquisition: the pressure transducer is configured in a full Wheatstone bridge, the input voltage and mV signal output can be connected to the same reference (mass)." Therefore, the mV output signal can be measured using a differential voltage measurement. Therefore, do not make an asymmetric measure of pressure transducer mV output. "(http://www.decagon.com/assets/Uploads/MeasuringUMSTensiometerswithnon-UMSControlandDataAcquisitionSystems.pdf)

  My understanding is that the 6008 can take a differential measure if I attach the signal '+' and the signal "-" to the analog inputs of positive and negative terminals. However, it seems that all the ports of ground on the 6008 are grounded to the same reference, which would make my measure of invalid tension according to the above paragraph. So my real question is: if I try to record the voltage with one of the analog inputs on the 6008 in this way, is the valid measurement? Or I need to find a separate power supply, with a different reference field to ensure that the measure is accurate?

  The technical details of this device is very poor. The manual is not much better. Companies that want to sell scientific equipment should publish decent cards or get out of business.

  In section 3.4.3 General requirements the device is described as a "bridge not amplified circuit.  This information along with the impedance of the bridge should be in the specifications, because it is essential to apply the device under any circumstances other than the nominal behavior in 10.6 V.

  The answer to your question is:

  You can use it with the box USB-6008.  The 5 V supply will result in output voltages a little less than half (5/10.6) the voltage specified in nominal conditions. You can use the differential input mode on the box USB-6008.  The absolute input voltages will be approximately 2.5 V with the 5 V power supply. This voltage is in the range of the aircraft. The differences are likely to be less than 100 mV. The resolution of the USB-6008 on the + /-1 V is located about 0.5 mV so your resolution of pressure will be about 1% of full scale. The voltage input impedance and termination of the USB-6008 will present a few errors.  These can be in the order of 5 to 10%. I can't predict much better without the missing bridge impedance specification.  These errors should be relatively constant and systematic. A calibration of the whole system - sensor and together hardware DAQ should allow you to compensate for a large part of this error.

  Lynn