The drift in analog of the PCI-6221

Similar Questions

• Need help on the use of the PCI-6221 and c# to control three digital Port and an analog of entry

  I need to send the digital output at three ports and then read an analog input voltage using the analog card PCI-6221.

  I did a c# program to fight against it. I built four tasks altogether. Three tasks for three digital output ports and a single task for analog input.

  How can I reduce the time?

  Using my method, to 3.3ms in total. And it's slow.

  I can build one task for three ports?

  What is the best way to the control task to reduce the time of communication with the PC?

  Is that possible to save a lot of analog reading entry in the memory of the DAQ hardware and then read it all together from the computer in order to reduce time consumption?

  1 million thanks!

  Hello

  Hi Jin,

  To answer your questions, Yes, you are able to configure a task of digital output to use three output ports and PCI-6221 has a buffer of memory FIFO aboard 4095 samples.

  I would like to direct you to the example of NOR-DAQmx for c# files located in the following location on your computer

  C:\Documents and Settings\All Users\Documents\National Instruments\NI-DAQ\Examples\DotNET2.0

   

  Here, you will find predefined examples in c# that should give you a good idea of how to go about architecting your code to achieve the results you need.

  There is also a useful help file which you will find by navigating to Start > all programs > National Instruments > NOR-DAQ > help of NOR-DAQmx .NET Framework 2.0

  I hope that this answer is useful.

  Best regards

  Steve H

• How can I activate several tensions trigger on the PCI-6221 using NOR-DAQmx?

  I use the card to make an acquisition of data simple PCI-6221.  The idea is to allow three different analogue voltages trigger the State of data acquisition.  I currently put code in place for a trigger voltage but I'm not sure what to do to add two additional trigger voltages. Any ideas?

  Thank you.

  Hi capncane,

  The 6221 is not able to do an analog trigger so DAQmxCfgAnlgEdgeStartTrig will not work for your card. Is your relaxation a digital signal? If so what kind of logic level is? If it's TTL, you can use the PFI lines. If this isn't the case, you need to trigger as I mentioned in my previous post.

• analog calibration on PCI-6221

  I don't get the volts per bit, I expect my Board of PCI-6221.

  I run the "Test Panel" available in v.4.3 Measurment & Automation Explorer.  I have a NOR-6221 multifunction with an installed interface BNC-2090 case.  When I run the "analog input" test, with entries dfferential and connected to ai8 ai0, I expect to 0 volt. The input values, the min max run defaults to-10 V + 10 V.  The graph shows zero + - 1 to 2 bits of noise.  See screenshot. The reported real amplitudes are + 0.000468, + 0.000144, - 0.000180, - 0.000504.  This corresponds to 0.000324 V/bit.  I expect to 20V / (2 ^ 16 bits) = 20V/65536 bits = V/bit 0.000360.  How to explain that gap of 10%? Thank you.

  Bill

  Hey Bill,.

  I could see a few things: with the M series, realize that the data returned by the ADC are not linear, so that V/bit varies over the range of the acquisition. Mcal allows us to correct the non linearity. Which may explain the discrepancy just here. Also note that the range is actually greater large - to make cal the range desired, some codes are outside the range of V 10 - generally of 5%. However this would actually push the V/bit upward. This is mentioned in the M-series user manual in the section of the analog input range . All this is taken into account absolute accuracy specifications so that they are still valid.

  Finally, when I calculate 20/65536 I obtiens.0003052 - which, once I multiplied by 1.05 gives moi.0003204, which looks a lot better. You may have swapped the 6 and 5, or the Windows calculator is fibbing to me once again

  So this brings me to my question - you notice the difference just theoretical vs measured and I was wondering what is happening, or you plan the use of this info? If you are looking to read binary (a common practice results in questions like yours), take a look at this KB when you get to the scale of calibrated data-

  3SKGA409 Ko AE: is raw data DAQmx calibrated and/or scaling?

  Hope this helps,

  Andrew S

• How to detect the relay ON / OFF state with PCI 6221 analog input card

  In order to test if a relay is ON / OFF using my card PCI 6221 DAQ devices and ports of HAVE it.  I conect of the relay contacts to an AO giving 5 v and the other contact to an AI in order to detect the corrent.  In addition to a bridge is necessary to close the circuit betweeb the AO and AI.

  Shoud this bridge conect the MASS of two ports?

  The plan is: relay - AO (5 v) - AO GND - GND AI - AI0 -.

  This does not work and gives a continuous corrent to 10 V (I think it is a saturated)

  Hint, please?

  The simplest connection is:

  • One side of the relay contact: + 5V PCI 6221
  
  
  • Other side of the relay contact: all DI PCI - 6221

  But I would add a DI (for example 10 k) resistance to GND of the PCI 6221. This will outline the entrance to GND when the relay contact is open.

• Impossible to test, check, calibrate the card (PCI-6221) DAQ with MAX

  Hello

  We bought a PCI-6221 DAQ card and we have installed. However, it seems that the device is not recognized. First of all, it appears as a device in the PXI system then that is a PXI system. Then, I don't have access to the 'properties', 'self test' and "to calibrate" menu. This issue should be linked to the first.

  I tried to remove the driver and install it again, but it didn't work, so I tried the update but it is the latest version. Is there a problem with the driver?

  I checked with Labview if it was possible to use it, but no devices were found by the DAQ assistant. We have the whole NI Developer Suite 2009.

  Thank you for your time

  Cedric THOMAS

  Hello

  It works! Great! Thank you very much for your help.

  However, does this mean that DAQmx 8.8 is having trouble with the PCI-6221 device? Or I made a mistake during installation (but I have followed the manual)...

  I even can I create a simulated device also. That I couldn't do before with MAX 4.5.

  Thank you

  Cedric

• 5V power supply seems to have failed on PCI-6221

  I recently had a test set-up down, and it seems that this could be linked to the + 5v supply.

  When I connect 5v to the unit via an external power supply Board, the Board draws 50ma, far as the 1A, according to me, the PCI-6221 power is specified as being able to provide.  When I connect the camera Board to the PCI-6221 via cable, only 0.67v are measured on the map.  However, when the cable is not connected to the card of the unit, I measure 4.5V on the power supply 5v card PCI-6221.

  I couldn't find a standard of accuracy for the power supply of 5v, but I expected to be less than 0, 5V.  It seems that my PCI-6221 power can produce a voltage in open circuit, but decreases rapidly under a load condition, which seems that the jury didn't.

  Ideas?  Thanks in advance.

  Hi Scott,.

  Terminal on the 6221 5V is rail 5V PCI bus with some type of lighter, so the accuracy will depend on the computer's power. Would you be able to try this card in a machine that has a work data acquisition card? This would exclude any power problem on this computer. If this test fails, it is likely that there is a fuse and you will need to contact us as Josh mentioned for an RMA number.

• Triggering of a task by using PFI on a Board of PCI-6221 (37-pin)

  Hello everyone,

  I need material triggered acquisition, use of the PCI-6221 (37-pin) card board. In LabView, I used the simple program (see attachment): in a data acquisition assistant, the start of the task is set to 7 PFI. However, to make a PFI7 pulse does not trig acquisition and I get timeout error.

  When I test the same, but using the standard PCI - 6221 Council (i.e. 68 pins), everything works fine.

  I have to do extra to PFI configuration when I use the Council 37 pins? (Note: the same PIN is assigned to the PFI7 and digital line P1.7).

  Thank you.

  Jiri

  P.S.: I use LabView 8.0, OR-DAQmx 8.7.1 and Windows XP Professional.

  Problem was curious, but it is solved now:

  -OR-DAQmx wasn't actually 8.7.1 8.0.0; I have updated (but it still didn't work)

  -J' replaced the virtual channels by the corresponding physical channels; He began working

  -J' replaced return physical virtual channels, and it works always :-)

  It seems that there is a bug somewhere in OR-DAQ.

  Jiri

• I have a PCI-6221 NIC connected to a block of connection TBX-68. How can I see the wiring for the analog channels with MAX?

  Hi all

  I have a PCI-6221 NIC connected to a block of connection TBX-68. Once I found a drawing that shows me all the connections on my block of connection for each analog input tasks. I don't see this option now. Can someone describe to me how I can find this new?

  
  

• On the NI PCI-6221 fast sampling rate question

  Hi I was wondering if someone can answer a question of sampling rate on this card to PCI-6221 (http://sine.ni.com/nips/cds/view/p/lang/en/nid/14132).

  Especially if I wanted to transmit simultaneously (analog output) and data acquisition (analog input), what is the sample rate max I could use. Kind regards.

  Since the 6221 is multiplexing the analog input, your question for I / simultaneous ao is possible for one channel of the only. If your "simlutaneously" can include delays (e.g., 100us), you may be able to work with several AI channels as well...

  HAVE the multiplexes, workable sample rate given that the total sample (250 kHz) frequency divided by the number of channels that you use. AO is faster than HAVE it, so it does not reduce this number.

  hope this helps,

  Norbert

• PCI-6221 behavior off the power

  Hello

  A card PCI-6221, tension of the PC is out of snap-ins:

  When I inject a voltage (5V) input ana on the map, this tension is copied on the other analogue channels.

  Room I turn on the PC, and 6s after, injected tension is more copied on the other tracks of ana.

  What is the normal behavior of the map?

  Thank you pour your answers

  Hello Cedric,

  The behavior of the card when it is turned off is not defined. What is it you have a problem in your application?

  When you area PC, this one seems to provide power to the bus PCI 6 seconds after it starts, which explains why the map then adopts its operation.

  The best advice I can give you is to respect the configuration/connection of analog input (manual page 58 Chapter 4-14 M-series cards). About the card, if it works properly when the PC is turned on, and that the connection am well the guide, there is every reason to be reassured.

  I wish you a good day,

  Marc-Junior

• measure the distance between 2 impulses (PCI-6221)

  Hello

  I have a digital signal that sends a pair of impulses (100ns width each) roughly every 100ms and I measure the time between two pulses of a pair (with a resolution of 100 ns).
  For the moment, I got a card PCI-6221 to accomplish this task. Unfortunately, I have no solution until now only measures of counter, I found measure time between constant frequency signals, i.e. they cannot measure the distance between 2 single pulses.

  Any help / ideas / or even telling me that it is impossible to solve this task are appreciated

  Are the two pulses on the same line?

  If so, you need to just configure a task of the measurement period.  If they are on separate lines, you would use a task of "separation of two-edge.

  You might be to throw off by the timing of it:

  If you do not configure implicit synchronization in your task, will start on the first edge after DAQmx Read is called.  Thus, in order to intercept the signal, that you must configure your task, call DAQmx Read and then start your two squares.

  If you want the task to control the signal continuously, you must configure name timing.  In this case, you will receive a sample on each rising edge of the external signal (assuming that the two impulses on the same line) - If you start the task of counter before starting the production of pulses (which you probably should), then the same samples correspond to the time between pulses, the odd samples would be the time between each series of pulses.

  More information on modes of counting on the 6221 lie in the M series user manual.

  Best regards

• Blocking of blue screen with the analog voltage (WinXP, PCI-6251)

  Hello

  I'm looking to solve a problem of blue screen with my measure blocking
  application, which I am developing with C++. Blocking seems manifest
  a little random after a variable amount (500-50 000) of voltage analog
  measures. My application needs to make a huge amount of these digitally
  trigger voltage measures after a certain period of time, and I'm using a
  unique
  task to do. The task is stopped and started after a single measure
  is
  which is done around 10 000 - 100 000 times per second. For this
  because I do synchronized with the PCI-6251 map data acquisition and
  one
  Ztec oscilloscope card. It seems that the probability of blocking could be
  associated with
  the frequency of measurements of voltage that I perform.

  The
  the app itself is multithreaded, but I'm blocking concurrent access
  TO
  the card with lock - all access to the card are behind a single mutex

  lock, so simultaneous access is blocked. In any case, all data acquisition
  access
  o the map is initially a single thread, which is dedicated to the acquisition of data
  operations.

  I also did stress tests with Ztec scope map, which does not
  result
  in all the problems. I also disabled in order of acquisition of Ztec map data
  TO
  Make sure that it wasn't the card scope, the origin of the problems - the problem
  persistent, so this seems to point towards the direction of the nidaq map.

  The deadlock appeared when I used the original supplied with drivers
  the
  card. I installed the latest drivers (removed the device from)
  ' Windows
  Device Manager and your application Measurement & Automation, reinstalled), but the blue screen still appears.

  Blue screen gives me a few debug data, but it does not mention any

  files .dll or something that would be of course point to a specific file (driver). I enclose at least partially matching code snippets.

  Hello again! I've been in contact with a local support person, who suggested that I have use DAQmx_Val_FiniteSamps instead of DAQmx_Val_HWTimedSinglePoint. I don't have any other changes, but this (see below) and the problem disappeared, so this seems to be an acceptable solution, because I don't see at all why not do this way. (Thanks Henry!)

  DAQmxErrChk (DAQmxCfgSampClkTiming (task_reader, NULL, 100000.0, DAQmx_Val_Rising, DAQmx_Val_HWTimedSinglePoint, 1));
  DAQmxErrChk (DAQmxCfgSampClkTiming (task_reader, NULL, 100000.0, DAQmx_Val_Rising, DAQmx_Val_FiniteSamps, 2));

• In the resolution of the technical document ADC PCI 6221 = 16 bits at 250 kech. / s means I use all channels, then each sample channel = 15,625 kech. / S ?.

  In the resolution of the technical document ADC PCI 6221 = 16 bits at 250 kech. / s means I use all channels, then each sample channel = 15,625 kech. / S ?.

  Yes.

• I need to generate 3.3 V logic level Digital train of pulses with the NI PCI-6221. Can I change the level of 6221 OR logic output?

  I need to generate 3.3 V logic level Digital train of pulses with the NI PCI-6221. Can I change the level of 6221 OR logic output?

  The output cannot be changed. 5V to 3, 3V level controllers are readily available (Maxim, I think). As long as the scanning speed (etc.) is fast enough for your pulse train, even 3, 3V regulator would work. I don't know if NEITHER offers a module to condition TTL levels.