Analog output OR-6211 - tip of low voltage at the beginning/end of periodic signals

Hello

I use a data acquisition multifunction NOR-6211 at the exit of two analog voltage signals that are periodic. I read the values for the latter to a .txt file that is generated in Matlab. The two voltage signals are the same, however, one of them is 1/2 period out of phase from each other.

Here's my output information:

Frequency 100 Hz signal

Sampling rate of 200 k

Number of samples 2 k

Text files have 2000 samples in them.

When I look at the output on the oscilloscope, the first signal looks great, but the second signal is a voltage surge at the beginning/end of the period. I checked the .txt files and the first starts at 0 and ends at just above zero. The second starts at approximately 288 mv and ends at just below 288 mv.

I have attached my .vi and a .jpg file showing the Spike.  It stings to zero so I think it is a kind of buffer reset or something, but I can't understand this one... Any help would be much appreciated.

Thank you

Why are you converting complicated to and from DDT to get a picture of wave forms when you don't provide timetable information? Use Waveform build and build table as shown or just use the DAQmx Write DBL 2D value.

As Henrik, I fear that your data are not what you expect it to be. Put a graphical indicator or a table on the wires going to DAQmx writing to see what you have.

Lynn

Tags: NI Hardware

Similar Questions

  • read the output of a path of analog output current voltage

    In DAQmx if you are unsure of the status of a digital output port, you can take a reading on this subject.  When I try this on an analog output, I get an error.  Is it possible to query the status of the output of an analog output?  I realize that I could follow the State with a variable, but a direct reading would be really handy.

    Hello, GIS.

    There is no way to read the output in the AO modules without wiring physically the signal to a module to HAVE.  You are able to use a variable to read the current value of the output, as you mentioned earlier.

    Channels AO multifunction boards, however, can be read through tasks of entry by rounting in-house channel to read ao vs aoground.

    Lisa

  • To input analog shutdown when the analog output is completed and synchronization

    Hello

    I'm trying to get my LabVIEW program to send analog output to a computer and read acceleration using the cDAQ-9184. Chassis output that I use is the NI 9263 and the chassis of entry is the NI 9234. I generate a signal of white noise using LabVIEW Express signal generator.

    The first problem I have is the synchronization. I had an old VI that has begun to measure the acceleration just about a second after the entry has been given to the machine. I used the LabVIEW tutorial on how to sync the analog input and output, only to discover that it does not work with two different hunts. Then I found another tutorial that shows how to synchronize different frames between them.

    The second problem is the cessation of the LabVIEW program. What I want to do is to generate the signal and then simultaneously send and read the input and output analog, respectively. It is because I don't want a phase difference or any shorter signal for a direct comparison. But as soon as the signal is sent to the machine, I want the entry to stop analog playback and then then the LabVIEW program must stop. I want to be able to choose any length of signal to be generated and stop as soon as the entire duration of the signal has been sent to the machine.

    I tried 'DAQmx stop', "DAQmx Timer" and 'DAQmx's task made?' and none of them have worked for me. It is also my first time on a forum posting, so I hope I gave enough information. I enclose my VI as well. The VI shows I read an entry for the analog input voltage, but I am only using this to try to get to the work programme.

    I'd appreciate any help I could get.

    Thanks in advance

    Peter

    Hi Peter,.

    I have some recommendations for you that I think you will get closer to your solution. First of all, I assumed you meant that you had 1 chassis (cDAQ-9184) who had two modules in it (NOR-9263 and NOR-9234). My next steps are based on this assumption, so if it's wrong, please let me know.

    For your first question about the synchronization, the code you provided is very close to what you need. You need to do, however, implement architecture master/slave for startup tasks DAQmx functions. To do this, you can add another frame to the flat sequence structure and put the master start task (input voltage) after the start slave (output voltage) task.

    To manage your second question and that the program ends at the point where you, the first step is to get rid of all the logic that you use with the local variable of length of time. Rather than use this logic, just wire the node "task performed?" of "is task performed?" operate to stop the loop. This will cause your loop to stop as soon as the signal is sent to the machine.

    I have some other recommendations for you that will increase the performance of your program:

    (1) rather than writing on file inside the last loop, you can use the DAQmx Configure Logging (PDM) .vi. You will place this VI between DAQmx Timing.vi and DAQmx Start Task.vi to the task of the analog input voltage.

    (2) after the last while loop, you want to stop the task and analog outputs as well with another DAQmx stop Task.vi.

    (3) rather than using a local variable for the entrance of displacement and wiring it in the DAQmx Write.vi, you can wire directly from the output waveform of the wave to build function node.

    That should help you get started in the synchronization of these tasks.

    -Alex C.

    Technical sales engineer

    National Instruments

  • Reconciliation of analog output NI USB-6210

    Using Labview, I am currently using an NI USB-6210 to produce a signal that a BOP of Kepco 50-2 M feeding programs. Unfortunately, this device NOR produced no analog voltage. Is it possible that I can use the digital output or against the unit OR to do something that approximates an analog output? I need a way to get the power output voltage has the supply to increase gradually in a predefined way. I only work with a couple of volts because of sensitive equipment, so accuracy is important.

    I don't have access to the program at the moment so I don't know what version of Labview that I use, but I'll be able to check in a few hours.

    Its probably not worth to use this device in a method not scheduled.  Cheeper with analog outputs are available.

    And don't forget the 4886 BIT card that can be purchased and hooked to your diet, there are even for using RS232 or GPIB device drivers to control the supply to

  • Digital, analog output file trigger

    Hello

    I'm trying to produce an analog output to text file. I have attached the text file with entries and file vi. When I connect oscilloscope, there is no waveform.  I'm using labview for two days. What is wrong with my code?

    Everything is OK now, I had a problem with the clock on board.

  • Read analog output channel value internally

    According to this you can read the values of analog output of return without having to physically connect the wires.

    By using the technique described in the example given (DAQmx_Read_Output_Internal_Channels.vi) I'm reading a current area of OCCUPANCY on my compactDAQ cDAQ-9174 with a module of analog output current OR-9265.

    The output channel is created in MAX and my vi can write values to him without problems

    But when I try to create an analog input channel to read the output, an error occurs.

    What I am doing wrong?

    This is not supported by my hardware?

    Or is the example given in the above incorrect link?

    The example is 10 years old. Maybe, it does not work in LV2013.

    Hi Jocker,

    The link was not attached to your message, but I guess that's it: http://digital.ni.com/public.nsf/allkb/CB86B3B174763C3E86256FFD007A2511 as there the example of vi you mention.

    The error you are getting is due to the use of the channel for analog output and trying to configure the task as a task of entry. You must use _aoX_vs_aognd as the channel of the task rather than on the output channel. This compares to the ground for the analog output values.

    The NI 9265 is not on the list of the C Series modules that have internal channels:

    http://zone.NI.com/reference/en-XX/help/370466W-01/mxdevconsid/9211interchan/#GUID-E13ADE46-5CB8-491...

    So I guess that the module is not able to compare its output to ground. He would appear in the dropdown of the channel names if available.

    Pete

    Applications Engineer OR

  • Control the analog output in *.vi

    Hi you all,.

    I have a PCI-6281 with a Bob SCB - 68 in any case, I use two channels of analog output to cross strains of certain instruments. Every time I restart the computer, I reset the tensions Explorer automization and measures. (I'm on measures and Explorer automization > devices and interfaces > NI PCI-6281 dev 1 > test panels... > analog output). Is there a way to have the VI set it each time I run it? THX

    Watch the DAQmx Write.vi in the DAQmx palette.  Also look in the viewfinder of the example (help-> find examples...) for the analog output DAQmx.  There should be a lot of examples that you should be able to disassemble to simply adjust the tensions.

  • Strange analog output of USB-6211

    I just got USB-6211 to replace USB-6001 to set the clock to external sampling on analog output for LED lighting control. The part of external clock example works fine, but the analog output voltage is strange. To do self-monitoring, I connected control pin LED to AO0 & AI0 of surveillance in the NI MAX test panel and LED control on the ground at AO - GND & GND HAVE since I have both USB-6001 and USB-6211, I conducted tests on two of them with the same setting of wire. When I generate sine wave - 5V to 5V to AO0 (from NI MAX test panel), USB-6001 can monitor the same signal AI0, but watch USB-6211 - 3, 4V to 3.4V voltage truncated. I did the test separately (wiring one device at a time), so there is no interference between the two devices. USB-6211 past self-calibration and self-monitoring. Also, I did reset devices. I don't know why they would behave differently with the same configuration, and I hope that someone could help with this question. Thank you.

    Hi skuo1008,

    The USB-6001 can support + / 5 output current my from terminals to analog output, while the USB-6211 box can provide only +/-2 my current output.  It is likely that the load impedance is too low, causing the 6211 to hit its current compliance and thus cut the tension.  If you try to exchange your load with a resistance of at least 5 v/.002A = 2500 Ohms, you should be able to see the full +/-5V sine wave.  I suspect that your DUT has a words 3.4V/.002A = 1700 Ohms impedance.  You could use a device with higher output current or use a more current source buffer circuit.  If you do not need a bipolar output, you might also consider using digital lines to control the LEDs.

    Kind regards

  • acquire the voltage output of a channel of analog output current

    I'm controlling a HV configuration rather sensitive analog output voltages. Is there an easy way to read the voltage level which is currently awarded by an analog output?

    Hello

    If you set your subVIs different voltages, you can be sure that the voltage you set in these screws are similar to tensions, you have to your output PIN. For example, you could write the value you give to the output in a variable and read this variable in you main VI.

    Kind regards

    Peter

  • Question about multi analog outputs voltage outfit

    I am programming my NI USB-6008 with V ++.

    Now, I have a question. The unit has 2 analog outputs.

    When I put the "ao0" channel to a certain tension, then stop this task. Start another task, then the string value "ao1" some tension. When I do the second task, ao0 held the voltage set in the first task?

    Thank you.

    Hi Lowsfer-

    Yes, the analog output of AO1 status will remain in the last State it was before the task is stopped.  As long as the device is not reset or the computer is not turned off, the analogue output will maintain the last tension that you specified, regardless of what did the other Ao channel.

    I hope this helps.  Good luck with your application!

  • Analog OUTPUT material

    Hello

    My question is about the analog output (0 - 10V) of the myDAQ unit.

    On the card, you can read:

    "Overdrive Protection +-16 V forever."

    Lets imagine the worst case: 0 V output DQA, but outside a battery or anything else is connected with 15 V to the analog output.

    Fact an "unlimited" current in data acquisition or protection 'Overdrive' works here and the material is safe to destroy?

    The background: I want to OD are protected from transient voltages and toilet on a simple zener diodes clip or a tvs diode...

    Thank you all, Markus

    Markus,

    To use a zener diode as protection, you must also have an impedance of current limiting in series with the source against which you are protecting.  The manual for the device of maDAQ indicates that the lines of the AO are pushed by OPA1642 op amps.  TI the MSDS for this unit shows the current limiting internal ~ 36 my short circuit with Earth and a thermal shutdown circuit that tries to protect against the terms of overpwer.

    However, under your 15 V battery, 11 V zener and 0 V programmed DAQ exit, the situation may be different.  The current from the battery through the zener will be limited by the impedance of cables or any type of resistance on the line.  This has no direct effect on the myDAQ device, but it will probably destroy the zener unless resistance limits the current to a lower maximum current nominal zener.  As long as the voltage at the output of the myDAQ is lower than the internal supply voltage (+/-15 V), on the OPA1642 current limitation should apply.  With 11V applied to the output and the value set to zero the device would probably be to try to sink the maximum current for-15 V power supply.  Which translates to a dissipation of power of more than 900 mW, which exceeds the rated capacity of the op amp. Themal protection should, in principle, reduce the current to a level that does not exceed the thermal limit under development.

    This test can be a costly process. The unit may be destroyed.  Given that the maximum current specified for an analog output channel is 2 my and the maximum voltage is 10 V, I would consider a series resistance of perhaps 1000 ohms and clamping schottky diodes at the + 15 V and - 15 V power supply.  This will limit the current to 10-20 my in all conditions you have mentioned and would also provide protection to the case where the battery is connected the myDAQ device is turned off. He alsoe does not care about the polarity of the external source.  It will drop the output voltage according to the load impedance.  If this should be used in a student lab, the calcualtion of this decline is something they should be doing anyway, and would be a small price to pay for protection.

    Lynn

  • DAQmx: Analog input directly to the analog output at the hardware level

    Hi all

    I searched for a while, but I couldn't find any suitable implementation for what I'm trying to do.  A person where I work introduced me to an interesting challenge.  Is there a way to set up a DAQmx task (or set up otherwise an MIO Board) to route an entry directly to an output to the analog analog hardware level?  You may be thinking, "why the hell would you do?  To reduce the electrical complexity, a colleague would like to concurrently read an entry while 'reproduction' of its signal on analog analog output.  I know that I can easily accomplish this while the buffering by the PC, but they are interested in ensuring that the output signal is also similar to the input at the level of KHz signal, by introducing a minimal difference in phase (shift buffering of the PC).

    For the record, we have for most old maps of the E series here like the PCI-6070E (PCI-MIO-16-1).  I was first asked if it could be done through SCXI, but I figured I would start by asking about the MIO tips.

    This looks like a long shot, and I've never heard of someone at - he never did this, but I thought I'd ask to be sure!

    Thank you

    Jim

    Hi Jim,.

    With the help of our driver is not a means of generating data directly from the FIFO of AI, it must first pass through the software.  You can try the following code to the output of one of THE duplicate on the AO line to see what kind of delay you can imagine.  It is similar to your original with a few adjustments code:

    Use delayed output Version of avian influenza in DAQmx AO

    It seems you need to do, you might consider instead the search by using a voltage follower to isolate the Vout wine.

    Best regards

    John

  • Simple examples of analog output USB-6343

    I've tried passing by 'find' examples and does not know how to find what I want.

    I'm doing a simple analog output on a USB-6343.  Examples of waveforms say they work with the USB-6343, but I really don't want a waveform, just analog of output does not exceed 10 Hz speed of renewal.  Some of the more simple examples show that they work with the pcie-6343 but do not list USB-6343.

    I worked with USB-6009 in the past, but when I try to use an analog output task that uses 1 sample on request, I get the error "not buffered operations clocked by the hardware are not supported for device and channel type.»  Set the size of greater than 0 buffer, do not set up the timing of the sample clock or the value Type of sample On Demand time"

    I tried samples N, 100 samples to write to 10 Hz - the same error.  Samples of continuous - same error.  1-sample - timed HW - same error.

    There is a series of examples of I/O for the X series?  Is it possible to search the device examples rather than go through all the examples and by checking the list of devices individually?

    Is 'size of the buffer' the 'writing samples"in MAX?

    After contacting the support I was provided with the names of the more simple examples for analog i/o:

    Analog output-Gen power Update.vi

    Analog Input-Acq & chart voltage-Int Clk.vi

    They are found in the getting started screen of

    Click 'Find examples' near the lower right corner

    Filter the results to material by clicking on the menu drop down for the material in the lower left corner and selecting USB-6343 (only connected equipment will be displayed)

    Don't forget to check the box "limit results to material" below.

    In the center pane, double-click 'Material Input and Output'

    Double-click DAQmx

    Path for the analog input - double-click Acq & chart analog measures - double click on tension - tension-Int Clk.vi

    Double click on analog generation - double click on Power - Gen Update.vi of analog channel output voltage

    The examples are for the single data point.  Samples and exit multiples are produced by putting the writing or reading VI inside a loop.  The beginning and the clear functions should be out of the loop.

    Additional information, I need technical support was how material-filter results and identification of more simple examples which were not obvious from the examples of names.

  • Analog output of signal generation custom

    Hello

    I have a VI that generates a signal from the values in an excel worksheet. I'm trying this waveform through an acquisition of output data. I use a box NI USB-6211.

    I copied the exit code for the acquisition of data from other VI that generates a sinusoidal signal coming from an excel worksheet. This program works very well. (attached for reference - Analog Output VI + sinusoidal waveform)

    I have two problems at the moment. First of all, I get error-200560 about waiting until the function, attached.

    Second output amounts only to about 5.5 v instead of 9V specified in the data.

    My VI generate several types of waveform according to selected tests, but I'm trying to get an output DAQ working with the first test, named "disconnection of the battery" work first before implementing it in the other tests so please ignore others for now. To run this battery select VI disconnect under tests select then direct to the attached excel (BD values under 10V) file.

    I hope that I myself have pretty much explained, otherwise please ask for more! I'm new to LabVIEW so your help would be very appreciated.

    Thank you very much

    Parker

    aeParker wrote:

    I've made a few improvements to the VI but I always feel the DAQ 5 Cap output, 5V.

    Dear Parker,

    I guess that this statement is based on the values in the chart show, AO 0.  However, this is not (necessarily) the voltage produced by AO 0, but rather the tension being sampled by AI0.  If you look at the DAQmx create channel for the AI voltage channel, you will see that you have left entries Maximum and Minimum Value unwired, which means that they take their values default to + 5v and - 5v.  This may explain the behavior of cutting that you observe.  Try the + 10 and -10 wiring and see if that solves this problem.

    Bob Schor

  • Using the DAQ USB-6009 meter and an analog input voltage at the same time.

    Hello

    Currently, I'm reading the two channels of voltage with the USB-6009. It happens that one of the channels is the output of a digital coder, and it would be much easier to use it directly to the PFIO entry that is defined as a counter. The problem I am facing right now, it's that I can't use the DAQ Assistant to use the analog voltage to a channel and the digital channel counter at the same time. Once I put the DAQ Assistant to read the input from analogue voltage, I won't be able to add analog inputs. And as I put the DAQ Assistant to use the PFIO as a counter, I can add more entries to read analog voltage is.

    I wonder if it is possible to solve this problem using the lower level data blocks? Another solution would be to read two channels in analog input voltage and that the use of Matlab to process data resulting from it, since I was not able to do the counting to work simultaneously with the acquisition in Labview to impulses.

    Hope you guys can help out me.

    Thanks in advance.

    Using a simple wizard of DAQ is incorrect. You need one to acquire analog inputs and one for the meter.

Maybe you are looking for