USB-6251 continuously current monitoring

Similar Questions

• How output waveform desired by USB 6251?

  Hi all

  1 I have problem like this: now, I use Laview 7.1, NI USB-6251, I want to output with desired waveform (shown on the attached picture). I want to know: 6251 USB can perform this problem. If Yes, can you advice me to solve it, I'm most recent with Labview.

  Waveform details: start I want to output current train of pulses with the decrease in the amplitude, until the amplitude of the current touch 0, after that USB-6251 output current with waveform of Sawtooth (but flat at the top sawtooths).

  Waveform of power like this:

  

  2 I want to know: what the higher frequency and the amplitude of the pules (or / and sawtooth) which can produce the 6251 USB?

  Can you show me how to download files, and Image to my message? I wat to download the *.vi file and the image of waveform of the current as I write.

  Thanks in advance for any help!

  CUONG. NM

  Hi Cuong,

  The modules of the series C, such as the NOR-9265, can be used in a chassis for CompactDAQ 9172 - OR . This chassis is connected to the computer via USB, and contains 8 slots for modules of the C series as you want. My recommendation for the type of installation you need would be to get an analog inputs NI 9205 module, but also a module e/s digital NI 9401 for use in the cDAQ-9172. For a complete list of the C Series module and the description of each, please see titled knowledge base "supported C Series Modules in the cDAQ-9172 CompactDAQ OR.

  "" Using the NOR-9265, you will be able to use similar example DAQmx programs to accomplish your task, and these examples can be found in the Finder example under input and output material"DAQmx" analog generation ' current. Unfortunately, these three devices mentioned in my last post are currently the only options available for the current production and the cDAQ chassis is the only USB solution. Hope this helps also,

• 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.

• Filter low pass analog (anti-aliasing filter) external to the NI USB 6251 housing

  Hello everyone!

  -I m trying to acquire an analog signal of tension (high frequency content) using a connected to an edge NI USB-6251 BNC-2110. I learned in this Labview Forum that NI USB-6251 has no analog low-pass filter programmable (or anti-aliasing filter), so that I can't help but jitter when scanning my signals. For my application, the cutoff frequency of the analog low-pass filter must be equal to 100 kHz or MORE (maximum of 500 kHz). A possible solution to solve my problem, would be to work with an external analog low-pass filter before you scan the voltage signal. Based on this I'd like to know:

  (1) national Instruments develops analog external filters? I need a filter which also has one output, analog, so that I could send also the low-pass analog filter filtered signal to my NI USB-6251 box to scan correctly it!

  (2) what model of external low pass filter would be compatible with the NI USB-6251 housing?

  Any help would be much appreciated!

  Best regards!

  Hello

  all high resolution of the M series (628 x) cards are equipped with a filter low pass which can be enabled or disabled programmatically. For the anti-aliasing filter feature, examine the boards of National Instruments DSA (dynamic signals Acquisition) acoustic and vibration measurement
  currently the NOR 9221, 9225, 9227, 9229, 9233, 9234, 9235, 9236, 9239 and 9237 C Series modules feature anti-aliasing filters. These modules are intended for the high accuracy measures for which anti-aliasing filters are a necessity.

  Houssam Kassri

  OR Germany

• Not recognized USB-6251 (detected) to the MAX but is detected by the Windows 7 Device Manager

  Does anyone have a solution to our problem?

  USB-6251 is not recognized (detected) in MAX but is detected by the Windows 7 Device Manager.

  Is our configuration: Windows 7 (64-BIT), DAXmx 9.3.0f2, MAX 4,8 and USB-6251 (S/N 12B647A. P/N 194929 D - 04 L)

  We had a 'ready' indication/led the 6251.

  We tried several things... (all do not work)

  1. we have installed DAQmx 9.3 (for Windows 7)

  2. clean MAX Database by the following

  http://digital.NI.com/public.nsf/WebSearch/86256F0E001DA9FF86256FFD005B827C?OpenDocument

  Michael B.

  Yes the 6251 appears as a DAQ hardware.  Device charger OR placed in the auto-start services window.  We have refreshed MAX.

  Success!  I had to manually start the device loader.  Even if the service has been set to autostart, it did not work.  Right-click on the service shows that the beginning was selectable.  Click Start and the service began.  Start to MAX and can now see the device.  Open the front panel.

  How does the monitor devices OR running in the interface of the status bar to the device loader service?

  I don't understand why the service was not working.  Is it a security issue?  I am logged in as administrator.  I'll try once again as a normal user.

• How to reduce the noise in an acquisition of data USB-6251

  Hello world!!!

  I have a few questions about a system that I have developed using a data acquisition OR usb card 6251. The pressure control system.

  First of all, the signals are acquired using an Omegadyne pressure transducer. (Typically, the signals are between 0.1 mV and 38 mV, pressure is between 0 to 50 lb/PO2). The transducer is connected to the usb-6251 daq card (I use pinout of the 1 and 2 for the signal acquisition, also, I have a 100 K resistor between pin 2 and 3) and the card is connected directly to the computer. In addition, I have an omega counter, I use it only to see pressure on the screen. But long term, it will be useless.

  One of the problems I have found is the noise, the measured voltage values change much. Even if the figures in the player screen do not change so much... (or do not change)
  The system should regulate the pressure so if every second it changes a lot, the system did not work properly. How can I make the technical more similar to that of the meter? In the labview program that I use, I use a block 'base DC', he reduced noisy signals a lot, but not enough that experience, I need more stable values.

  Thank you

  I don't mean in the /manuals of broaching and do not open .doc from unknown sources files (a chart single .png is fine ;-))

  However, I guess you already measured in differential mode and the 100 k is a path for the currents of polarization forever

  The reason why your counter is stable can be the fact, that she has a generation to filter low pass (on average) with a big enough constant time.

  First things to do:

  You did it that there is a filter anti-aliasing suitable for your sampling rate?

  Read the signal on at least 100 ms (120ms in line 60 Hz) possible higher sampling rate and take a look at the signal (and display a chart as a .png or .jpg image)

  This will give you an idea how the signal looks the same. Then you can choose a filter according to your system and the signal or other investigations to do not even catch the noise (groundloops, protection...)

  You can use an example on the screws or the testpanel to the MAX for this measure.  (Personally, I prefer a similar scope :-))

• I have to check if NI USB-6251 is active by program

  I do an automatic capture of a series of signals through the 6251, I need to check a program if the device is very active and connect to another device to send the signal.

  Currently there seems to be a delay after I called BeginReadMultiSample and it is not compatible, so I can't just add an approximate time.

  If some of the signals are not captured at all since the NI USB 6251 case had not become active even after that I called BeginReadMultiSample. is there a way I can query the status of the device through program. (I use c# with NationalInstruments.DAQmx.dll)

  Thanks in advance

  Hi Raghu,

  Is it ok for you if your data acquisition starts before the real signal? If so, then what I suggest, that is after giving BeginReadMultiSample command generate some dummy signals to any channel DIO/AO free and acquires some other channels HAVE. Wait for the signal to acquire before sending the actual relaxation to your signal generation device.

  It is not the best solution, but will serve your purpose if you are fine with others a few samples at the beginning.

  I hope this helps.

  Kind regards

  Héloïse

• My usb port on my monitor is low how can I activate it

  My usb port on my monitor is low how can I activate it

  Hello

  I would check the cable first, but what is your machine and its monitor? One of my monitors has a separate cable that come with the monitor for these 2 ports, 2 USB ports on the left hand side.

  Kind regards.

• NI USB-6251 - Signal Express - Input Ports display signals idential

  Hello

  I plugged a DET50B (phototedector) at the port of entry Ai0 in my case NI USB-6251 and thanks to LabView SingalExpress 3.0.0 took a look at the Ai0 signals and Ai1 by clicking on the following points:

  Acquisition of Signal-> DAQmx acquire-> analog input-> voltage

  I was expecting the Ai1 signal or 0 Volt, because there is nothing connected to it and the Ai0 signal vary in what concerns the light I was shinning on the photodetector. Instead, the Ai0 amplitudes both Ai1 were identical and corresponded to the light I'm shinning.

  How is it that these ports appear to be connected? It's the same thing when I opened other ports for viewing by SignalExpress except the Ai8; This one seemed to be at zero (probably because he does not physically exist on the NI USB 6251 which Ai0 - Ai7).

  No, you will not read 0 Volts to a channel not connected. Do a search for 'ghosts' for a detailed explanation. If you want 0 voltas on a channel, you need to gnd.

  p.s. You do not have a signal generator Board. New questions should be mailed to multifunction DAQ and Signal Express cards

• locking using NI USB-6251 amplifier

  Hi all:

  I'm in the very initial stages of development of spectroscopy (FMS) frequency modulation experience on my set-up of already existing absorption spectroscopy. I know that I'll need an amplifier to lock to select the signal at a specific frequency. I already have an acquisition card of NI USB-6251 data which works very well and I've used for my experiments of absorption spectroscopy. I was wondering if there is a way to create an amplifier to locking vi which uses the NI USB 6251 casing and would do what I need for my FMS experience. I try to avoid buying another instrument, if I do not need.

  Anyone who is familiar with amplifier locking vi and see if I can put it with my USB NI 6251? Thank you!

  Alfredo

  Herea link to the use of an amplifier to locking using LabVIEW.  However these specific VI were designed to use our acquiring dynamic signals of maps that isn't the 6251.  You can try using a simple bandpass filter in the software, but it is certainly not an ideal situation in any stretch of the imagination.  But with only the 6251, it is certainly an option.

  Kind regards

  Brian P

• How to sync 3-way with USB-6251

  Hi all

  I have a NI USB 6251, Labview8.5.

  My system includes: + a waveform output stimulating (I use Dev1/AO1 or Dev1 / AO0)

  + Two channels for (I use Dev1/ai0 and Dev1/ai1) acquisition of input signals.

  I modified example "Multi-multifunction-Synch I-AO" Find example\Hardware entry and Output\DAQmx\Synchronization\Multi multi-function.

  I added a single channel for this example and I want to 3 channels at the same time working, but during process occurs "error-50103 occurred at Task.vi:1 DAQmx Start" or the possible reasons: the specified resource is reserved. The operation could not be performed as indicated.

  I have taken a long time, but can not solve this problem.

  Can you give me any advice.

  Thanks in advance for any help!

  MC

  As the specifications clearly indicate, your Board does not support simultaneous sampling. There is a simple element A/D and all channels are multiplexed for her. When you select several channels, the first string in the list will be sampled, then the second, etc. There will be a time that you can determine and it is very small, but it will always be there. If you need simultaneous sampling of the value true , you can buy a DAQ card that supports.

• C++ Interface USB-6251

  I know this has been asked to death, but I have not found an answer very clear on google or on the forums. I have an acquisition of data NI USB-6251 I want to interface with the help of C++. I have Visual Studio 2008 (or VS 9.0), but I don't have a Measurement Studio. I would avoid buying Measurement Studio if someone knows interfaces with Renault C++ sample codes?

  If you DAQmx installed, you should be able to go to start > programs > National Instruments > NOR-DAQ > text in support of the Code and find some relevant examples there.

• USB-6251 power(+5V) LED is not solid but flashes when turned on

  Hi all

  I have been using USB-6251 for 3 years without problems until last week.

  Since last Thursday, when I turn on the Board of Directors, the power led (which is located on the top, we write also POWER (+ 5V)) starts to blink and my laptop does not recognize the Governing Council.

  Before this problem, when I turn on the bud the power led was solid and my laptop automatically recognizes the jury.

  I'd be happy if someone can help me to know what happened to my Board of Directors.

  Thank you!

  skim,

  I would try a couple of things:

  (1) try a different USB port on the computer, and probably not the question, but a good starting point.

  (2) validate the external power supply you are using is to show the voltage it is assumed.

  (3) try another computer if you have one.

  (4) check the fuse (Details) USB device and see if it is blown. I can't find anything in the M-Series user manual the retail why should 5V power light blink.

  If none of these work, then the best option is to return the material to the OR and get it fixed.

  RMA procedures for hardware details are here.

• Tilt on a random channel USB-6251

  Hello everyone

  I hope that you will be able to help me with this problem that haunts me more than two years now.

  I use a USB-6251 box to acquire 3-way @100kS/s (acquisition of sample of N, N ~ 250 ksps), while simultaneously sending a result to one of the analog channels.

  In my application, the period of channel inter is very critical, that is, it must be precisely known (but not necessarily zero, although it would be nice).

  Not convinced by the results mediocre I got, I decided to perform a simple test to measure the impulse response (one so distort the channel) between the AO and the first 4 boards of my 6251. To avoid ghosting and keep the 4 AIs isolated from each other, I plugged 4 amplifiers contained in a TL084 IC in follower of voltage configuration to AIs, while feeding their entries with the AO signal outputs.

  I sent a Twitter and is its correlation with the acquired signals. The chirp was generating an impulse response "low pass filtered", in order to better appreciate the delays of the fractions of samples in the impulse response (IR).

  Some very confusing results: the IRs are randomly (by comparing the various acquisitions) place in the "t = 0" and "t = 1", very rarely to 0.<><1, while="" i="" was="" expecting="" to="" see="" 4="" irs="" "equi-spaced"="" within="" 1="" sample,="" since="" the="" 6251="" contains="" a="" single,="" multiplexed,="">

  The same random behavior can be observed by sending a simple sinusoidal signal and by checking that the 4 acquired signals are randomly out of step with the other by exactly 1 sample.

  I repeated the same tests in Matlab (using data acquisition and directly call the library daqmx) and Labview 8.2, still getting the same resut. I also tried (in Matlab) only change the sampling rate (as low as 8kS/s) and the number of samples acquired, without any significant change in the results.

  So finally, my question is: is there some kind of post processing going on behind the scenes which aims to align the entries, that fails somehow? Or is it because of some bad attitude? Would it be because of lack of samples?

  Has anyone else had similar problems with Renault multiplexed?

  Any thoughts on this would be highly appreciated

  Kind regards

  Giovanni

  
  

• USB-6251 can be programmed by vc ++ 6.0

  I buy a USB 6251 (DAQ), can it be programmed by vc ++ 6.0?

  Hi xiwang,.

  Yes, you can use Visual C++ 6.0 to program a USB-6251. Support for the USB-6251 added in point 8.1 of NOR-DAQmx. NOR-DAQmx 9.0.2 seems to be the latest to claim support for Visual C++ 6.0 (for the C ANSI API, not the Measurement Studio C++ API).

  Brad