Dynamic Biphasic Output to 8 Analog Channels

Hi everyone,
  First off, I'musing a PXI-7854R within an NI PXI-1402 chassis.  I'm just using the RMIO plugged into a SCB-68 to utilize the analog channels. 
  As for my VI, I'm trying to output a biphasic square wave to 8 analog channels simultaneously, but allow for variable high/interphase/low times and initial delays from a trigger.  I can output all the waves simultaneously and sequentially, but when it comes to fully independent output I'm running into some issues.  If I use the paradigm I've attached to this post, usually only the AO0 will output whille AO1-7 will fall silent.  I have a feeling this is probably due to timing issues/delays in the AO0 sequence, but I'm still getting upto speed with FPGA timing. 
  My method is rather simple and bruteforce.  If you have any suggestions for another way to go about this, I'd appreciate this.  We want pretty much all of the timing to take place on the hardward, which is why these delays are in the FPGA program. 
Any help would be appreciated.  Thanks much.
Attachments:
biphasic.JPG ‏259 KB

Disregard the timing question, I've figured that out.  If anyone has a suggestion for a more efficient way to generate this type of biphasic wave on the 8 channels, I'd still be open to getting that feedback!

Similar Messages

  • Splitting the 5.1 optical mbp/imac outputs into 6 analog mono channels?

    Hi
    is it possible to use the 6 outputs of the optical output of the macbook pro as separate channels?
    What do I need to convert/split the signals into 6 analog channels and does Logic/Ableton recognizes the 5.1 as 6 mono channels?
    thx!!

    sorry to tell you, but no. This is not possible. The 5.1 optical output is only possible by using a special digital encoding that comes with data reduction: AC3. You can't create AC3 streams without relatively large latencies and without buying rather expensive AC3 authoring software components.
    However, once you have an AC3 stream you can use ac AC3 compatible audio amplifier to convert it to analog signals. Not very feasible imho. The much simpler and less expensive way would be to buy an audio interface with multichannel support.
    Cheers,
    Jazz

  • Is it possible to multiplexe 8 analog sensors output into one PXI4472 channel?? can PXI4472 recognize those signals??

    I have around 64 analog sensors to connect to PXI4472. Instead of buying 8 PXI4472, is it possible to multiplexe 8 analog sensors output into one PXI4472 channel?? can PXI4472 recognize those signals??

    Such a set up is not recommended. Some of the drawbacks are:
    Depending on how you plan to multiplex the signals together (SCXI/PXI switch, 3rd party mux), you could very easily be introducing noise to your system.
    Multiplexing the signals together into one line limits your sampling rate to the switching speed of you multiplexer device.
    You will probably need to spend more time developing handshaking schemes in order for switching and acquisition to occur in such a way that you don't miss signals that you want to acquire.
    These are only some of the drawbacks to this setup. All in all, the only functionality of the 4472 board that you would be left with is it's ability to sample all eight channels at the same time. So, you could multi
    plex all the signals together, but doing so is not recommended.
    However, I have a couple of questions. Do you want to sample all 64 sensors at the same time? Assuming that you are not, how are you planning on multiplexing the signals together? What kind of a chassis are you working with? Please let me know.
    Logan S.

  • Power Mac G5 Audio is outputting only the right channel

    I have an audio problem with my PowerPc Audio card, I presume. It is only outputting the right channel. I have a set of computer speakers and when I go into System Preferences and move the balance slider, there is only sound coming from the right channel. Absolutely nothing from the left.
    I found this problem when editing in FCP and needing to do a split track with VO on channel 1 and Nats and music on channel 2. I could see the meters showing the audio output from channel 1 but no sound coming through the Mac's left channel output.
    Also, I have a DeckLink extreme card in my system and when I test the L-R channel output I get the same problem. I do not know if the decklink is somehow using the Mac audio card for help with its output. I would think that it is using its own hardware for generating the audio output from the card.
    Hardware issue? Time for a Mac Genius repair? Don't know if there is any workarounds or fixes before I go that route. Any help would be appreciated.
    Thanks
    Doug

    No I didn't but I run my Mac's output into an analog mixer and then out to my speakers.
    When outputting through channel 2 only, both speakers work, yet when I pan to channel 1 the sound drops out. As I pan from full channel 2, where both speakers are up full, you can hear the sound fade out.
    Also, I got the Deck Link card to work through my mixer. The L and R channels are outputting through separate inputs in the mixer and work independently and correctly. I even changed out the mini stereo cable just in case and still no left channel out of the Mac.
    Very weird! I've even repaired and defragged my system disk in case it is some sort of corrupted code. Just grasping at straws before I take it to a Mac Genius.
    Thanks for writing. I appreciate any and all suggestions.
    Doug

  • Best structure to measure voltage across 8 resistors in parallel via 8 separate analog channels

    Im setting up a simple circuit w/ 8 resistors in parallel. It will be connected to a PCI 6036E DAQ. I need to measure the voltage across each resistor, take x amount of samples, and then automatically move on to the next resistor and so on and also save the values to a file.  Im going to connect each resistor to a separate analog channel.  I have already setup a vi to read the voltage across one resistor and take X amount of samples, display the waveform, and also save the data to a file.  
    What would the best structure be to run this test?  I am thinking a Sequence structure, but it seems like people tend to avoid using that. Or would a case/while loop be better?
    From my understanding, the data will not pass out of a sequence structure until it is finished. this doesnt seem to be that big of a problem for me, as I only want the data at the end....
    thanks for the help!

    Use a for loop.  Put your code inside the loop, but delete the analog channel number.  Make an array constant and poplulate the array with each analog channel number.  If you wire the array to the loop (left side), you will see the terminal is a hollow box.  This means indexing.  The loop will operate on the first array element, then repeat with the second array element, and so on until all array elements have been processed.  Wire the hollow box to the point in your code where the analog channel number was deleted.  Now the loop will execute the same code using a different channel each time.  If you wire the output to the right edge of the for loop, you will again see the hollow box.  All of your measurements will be contained in an array at that hollow box.  Process the outputs as you like, maybe display the entire array, or index the array to get the individual elements, whatever.  The advantage of the for loop is that you have to write your code only once.  Everything is seen on one screen making it easier to read.  Sequence structures are not good programming practice because a lot of the code is hidden, and you have to go to different sequence frames to see the hidden code.  Also, why duplicate the code in each frame when the loop will do it all.  Good luck.
    - tbob
    Inventor of the WORM Global

  • Data aquisition from spectrophotometer in two analog channels, X-Y plot

    Dear colleagues!
    I am new to LabView and I am only starting to learn the system (I have never been a programmer, I'm a chemist to be precise).
    I have before me a task to interface an old analog scanning spectrophotometer to PC via LabView.
    It has two output analog channels: one is wavelength (two ranges, currenlty let it be 190 to 390 nm; it reads on multimeter as 0.19-0.39 V range) and another one is absorbance (0-1V range). An UV spectrum sholud be an X-Y graph wherein X is wavelength and Y is absorbance.
    I am able to read one channel OR another. I am able to read BOTH channels simultaneously, but how can I plot them AGAINST each other, not against TIME?
    I am using DAQPad-1200 (LPT interface) and LabView 6.1 (that's why I am unable to read most of the VI's posted on the forum ).
    Is such an interfacing even possible given my software and hardware limitations???
    Thank you all in advance!

    Thanks a lot, johnsold!
    I am now able to get something which looks like an UV spectrum! %)
    1. I will post an image (later); however, my primary objective is to get two columns of numbers, not necessary to see an X-Y graph onscreen.
    2. Without inserting arrays like I did LV always tells about error connecting this data line from two channels to save "2-D data to file" option telling me that input is 1D!
    3. I have a manual for the device, it has all of the schematics. I am no electrician though. I will post scanned circuit diagrams then when I manage to scan them.
    Now I see two more opportunities to control the device.
    A. There is a circuit (+12V DC) on the rear of one of the modlues, which, if shorted for at least 500 milliseconds (according to Tracor manual) can initialize automatic scan. How can this be done using Labview and DAQ device? My first guess is to use an analog output and some kind of a relay, either electromagentic or semiconductor one. Is there any other possibility?
    B. In my code I am always asked to write to a file after I initialize the sequence. Can this be done AFTER the sequence is finished?
    C. Finally, is it possible to automatically stop the While loop when the number generated by shift register becomes equal to 190?
    Here are attached a new code and a sample of data.
    Attachments:
    Tracor970A-v1.0.vi ‏53 KB
    UV-test-01.txt ‏15 KB

  • Acquiring data from all the analog channels of NI-3202 NODE using a single sensor

    Hi all,
    I would like to know that can i be able to get the data from all the four analog channels of NI-WSN node 3202(analog input node) connecting only single sensor on the analog input and connecting all the remaining analog inputs using wires and also shorting the ground pins corresponding to each analog input pin.
    By configuring the each channels like 0.5 sec delay for every analog channels to acquire data. can we get the sensor data from all the channels by doing this. basically here i am trying to increase the minimum sampling rate of the ni-wsn NODE 3202 which is 1s.
    I this approach is correct or we cannot do this.
    Thanks

    Stefan,
    In terms of differential and RSE, channels 0-8 should default to differential when using test panels.  Differential needs two input channels to function correctly and these channels must be spread apart by 8 channels. (i.e channels 0 and 7 are a differential pair)  Channel 13, on the other hand, will default to rse if chosen as the reading channel because there does not exist another channel that is eight away.  I am not quiet sure if the virtual channels will default channel 5 into being differential but I will check into it.  If it is differential as default then you may run into problems since channel 13 is utilized in both strain gauge reads.   
    "The second question is, if we can also use the "voltage" setting for measuring strain gauges? we did that in the past, using LabView 6.2."
    If you are referring to "voltage" as acquiring a signal with custom voltage with exciation then I would reccomend using example in LabVIEW called Acq Wheatstone Bridge Samples (with Calibration).  This can be found by navigating to LabVIEW's example finder and expanding Hardware Input and Output>>DAQmx>>Analog Measurements>>Strain.
    I have also included some useful links that may provide more insight into the SCC modules as well.  Also, what is the excitation voltage and power that your strain gauges are expecting?
    SCC Tutorial Series: SCC-SG0x
    SCC Example Series: SCC-SG0x
    Using the SCC-SG11 Shunt Calibration Module
    Thanks,
    Gio L.
    Digital Support - Product Manager
    National Instruments

  • I want to use two analog channels and one digital simultaneo​usly

    Hello and thanks in advance for reading this!
    What I am trying to do is generate two different signals from the output channels of my interface card (PCI6024E) and simultaneously use a digital line so that I can switch two tranzistors (one NPN, one PNP) which actually control the "flow" of the two signals. This means that both signals need to be "active" while the VI is running and at the same time whenever I want to choose the signal not in use I need to use the digital line so that I switch the tranzistors and I get the desired signal.
    I have already created a VI which activates a digital line and while I was trying to add with the NI-DAQmx Assistant the first digital output, I discovered that it c
    ould not be used simultaneously, because there was the error code -200324 saying that "Device not available in NI-DAQmx. It is possible that the device is being used by Traditional NI-DAQ or that the device is being reset."
    I did reset the device but as I get it when VI runs, it cannot have an active digital channel and an analog output channel at the same time (not to mention two analog channels). Correct me (And make my day if I am wrong but this seems to be the case. Thanks a lot for your time!

    Hey Shootist000,  Thanks for the replies.  First off, I am actually okay if we both have each other applications so I am not concerned about that. It is still unclear from what you have said as to whether I can in fact, use these two separte time machine backup to create two separate profiles on the new hard drive.  If that in fact can be done, then - will it create two copies of the apps we both have in the ROOT of the drive as well as placing all the ones we each have separately?
    And reading your second reply, makes me think that maybe the partition is the way to go to begin with and then down the road - after I am in the new iMac, I could reformat the iMac 27 with only one partion and restore my son's latest back prior to the reformat thus giving him full access to the 2 TB of the drive.
    If this is still making sense, does this mean :
    replace the 1TB with a 2TB - but have it partitione - 1.5 TB & 500 GB.
    Install(Restore using Time Machine) my latest back up prior to the  1.5 partition
    Install (Restore using Time Machine) my son's latest back up prior to the 500 gig partition
    Lastly, in order for us both to be using the partioned computer - I am assuming Switch user can no longer be used - so would we need to restart and select our respective partions in order to use the computer?   And if so, how would we each be able to be using time machine to back up - two separte external hard drives - with each one dedicated to only one partition? Or ? 
    Thanks so much.
    Ironically, I am only trying to do this so that I don't need to manually install all his apps, setting, games, blah blah for this temporary period.  :-)

  • Log an analog channel and counter period channel to hard disk simultaneously

    We are in a rush, and need to log one analog channel and one counter period measurement to disk simultaneoulsy using card controlled timing and set # of samples. Should be easy, but can't figure it out. Labview 6.1 we have & DAQ 6013E we just bought.

    Greetings,
    With regards to logging analog input data to file, I would suggest that you examine the examples available in the following location:
    Examples >> Hardware Input and Output >> DAQ >> Analog Input >> Stream to Disk
    Because you are interested in a finite number of samples, you should look at Acq N Scans to File (wdt).vi.
    With regards to logging period measurement data to file, I would suggest that you examine the following example:
    Examples >> Hardware Input and Output >> DAQ >> Counters >> DAQ-STC >> Measure Buffered Period (DAQ-STC).vi
    This example does not log to file, but it does demonstrate how to program a buffered period measurement. You will need to add the logging functionality to this VI as demonstrated in Analog Input >> Stre
    am to Disk.
    Good luck with your application.
    Spencer S.

  • Analog channel inserts with Logic

    I continue to struggle with Logic Pro to get an efficient work flow when I use analog channel inserts during mixing. If I insert an analog compressor on a single channel we all know that there will be a delay in that channel with respect to the other channels. My solution is to nudge that channel to the left in anticipation of the delay. Supposedly, Nuendo and ProTools HD automatically compensate for that delay when an analog insert is used. I have hard time keeping track of which tracks are nudged to the left and which aren't as I am trying out various inserts.
    I must be missing something. There has go to be an easier way. I vaguely recall someone mentioning something on a forum about a third party plugin that has the ability to correct for track latency.
    I would appreciate comments from anybody using Logic with analog inserts. I am getting frustrated to the point that I am strongly considering picking up PTHD or Nuendo for this very purpose.

    midnightsun wrote:
    I continue to struggle with Logic Pro to get an efficient work flow when I use analog channel inserts during mixing. If I insert an analog compressor on a single channel we all know that there will be a delay in that channel with respect to the other channels. My solution is to nudge that channel to the left in anticipation of the delay. Supposedly, Nuendo and ProTools HD automatically compensate for that delay when an analog insert is used. I have hard time keeping track of which tracks are nudged to the left and which aren't as I am trying out various inserts.
    This is NOT true. I have used both whilst using external compressors / reverbs / et al, and you still have to manually move the processed track afterwards. What I do, is process the track into a new recording, and then line it up. then use the compressor for something else, or remove it from the signal chain.
    I must be missing something. There has go to be an easier way. I vaguely recall someone mentioning something on a forum about a third party plugin that has the ability to correct for track latency.
    There is, you can use Logic's built in sample delay plug-in on all the OTHER tracks, the ones that are not going to the external device. Do a test where you find out the IO latency for the compressor or device, and set the sample delay accordingly. If your workflow demands it, that's the way to go.
    I would appreciate comments from anybody using Logic with analog inserts. I am getting frustrated to the point that I am strongly considering picking up PTHD or Nuendo for this very purpose.
    I do use them all the time, I have a bunch of outboard, which I use for tracking and mixing. I also have used PT HD and Nuendo in these very types of situations.
    Again, you would be wasting your money. NO DAW can give you automatic delay compensation for UNKNOWN external devices. This cannot be, and this is why:
    1. Once a signal has travelled to the physical output of the computer, there is NO WAY the computer can know where it goes, how long it takes to go there and come back. This is analogous to you throwing a rock around a corner, and knowing that it will go all around the building, WITHOUT LOOKING. And also, when a rock comes all the way around the building, it hits you, and you KNOW that's the same rock. This Physically Impossible. If you are skeptical, try it for yourself.
    2. Likewise, a computer cannot possibly know that an incoming signal is the one you sent out previously. This is, because a computer cannot THINK. A computer COMPUTES. It does math for us, so we don't have to. We still have to tell the computer what we are inputting, and we also have to know what to do with what it outputs. One day, many years from now, we might have some AI in our computers. Yechhh. I like thinking for myself.
    Cheers
    Message was spellchecked by: comatose priests on a mission to get caffeine

  • How can I detect an error on a single FP analog channel?

    Hello! I am new to the world of LabVIEW, maybe someone can help me. I need to detect if ONE of the analog channels in FP-AI-100 is in error state, such as reading out of range. I have no access to working FP modules and have no way of testing my code. Could someone tell me if what I am trying to do is possible? I modified an example Analog Input.vi and wondering if it will work. I changed the input to Read block to read only one channel, not the whole module and examining the error status bit. Will this status bit display error only for selected channel or for the whole module? I need to ignore all other channels.
    Thanks! Ellen.
    Attachments:
    Analog_Input_Error_Test.zip ‏12 KB

    Hi Ellen,
    I do not have LV 7.1 loaded so I can not look at your VI. Please post an image if you want me to look.
    In theory, checking the boolean should work in finding error cluster that have the boolean set.
    THe complication is this.
    I have seen that some of the error codes returned by FP reads will either have or not have their booleans set depending on which version of the FP code you are using.
    I saw in LV 6.1 that an "open RTD" (if memory serves me correctly) would return a true boolean if LV 6.1 was the latest version of LV loaded. After another engineer used LV 6.1 after he had loaded LV 7.0 the error boolean was no longer set!
    THe definition of boolean set or not set from one version to the next!
    So...
    I must advise that you test each
    type of error you want to support in your code with whatever version of code you plan to use to ensure the boolean will be set.
    Trying to help,
    Ben
    Ben Rayner
    I am currently active on.. MainStream Preppers
    Rayner's Ridge is under construction

  • How to store the output of a analog to digital converter into an 2D array

    Hi
    I am doing my M.Tech Thesis in Image reconstruction and I am using labview for simulation and I want to know how to store the output of a analog to digital converter into an 2D labview array.

    nitinkajay wrote:
    I want to know how to store the output of a analog to digital converter into an 2D labview array.
    How exactly are you performing 'Analog to Digital'???
    Grabbing image using camera OR performing data acquisition using DAQ card OR some other way????
    I am not allergic to Kudos, in fact I love Kudos.
     Make your LabVIEW experience more CONVENIENT.

  • Re: DAQ write+read analog channels

    Thank you Dan,
    The device used is NI_USB 6211 and the tests will be done by another person.
    So from your email I understood that is not recommended to use Hardware Timed Single Point.
     And just for my information: in your example what happened if I will try to read two adiacent analog channels (that means analog->multiple channels->single measurement)? It is possible? I'm asking because then we have a multiple point...right?
    Do you think this USB device will work at 5 KHz rate?
    Anyway it seems it must be used sometime even at 10 KHz.
    So I still waiting for a guaranted solution!

    unintentional dup post.  see here for discussion
    Jeff

  • Crosstalk among Analog channels

    The setup is this :
    1. Card is PCMCIA 6024E.
    2. Software is LV 7.1 and all reads are with DAQMx functions.
    3. 6 analog channels configured in differential mode ( AIN_0 to AIN_5)
    4. Connected to the card via BNC2110 connector.
    If I connect only one channel to a signal, it is reflected in all the other 5 channels at different levels.
    I do know that I can solve this problem by two means :
    A. Ground the unused channels to AIGND.
    B. Use alternate channels with one grounded channel in between two active channels.
    In my case since I need all 6 channels at times, so option B does'nt exist.
    Question is, can something be done in the software without resorting to option A.
    I have attached the snap shot of my problem. The straightline plot is the channel that has a signal on it and the other "followers" are free channels. At 15:49:43 I made the active channel zero and you can see all of them dropping to zero. Then I started another channel and all of them pick up !
    Kindly help solve this.
    Raghunathan
    LV2012 to Automate Hydraulic Test rigs.
    Attachments:
    FuelPump_06-04-05 _PM 03-50-08.jpg ‏86 KB

    SE_Hoard wrote:
    I would be interested in any solutions to your problem also. ... When I input a signal on CH0 it also appears on the other 7 channels. ....
    I was searching the tutorials and application notes on the NI site. Located this PDF which discusses the aspect of amplifier settling times in a multiplexed front end of a multi channel DAQ setup. Just read through the recommendations and see if they can help to reduce crosstalk in your case :
    http://zone.ni.com/devzone%5Cconceptd.nsf/webmain/B9B5D37A04C772B58625686500695C20/$File/AN045.pdf
    Raghunathan
    Raghunathan
    LV2012 to Automate Hydraulic Test rigs.

  • DAQ write+read analog channels

    Hi,
    I need some urgent help to solve a simple problem:
    My job is to write an analog channel to a DAQ device and then to read two analog channels from the same device.
    These should be done at the 5 KHz rate.
    For smaller rates I can do it using normal loops (or timed loops). But I don't know how to do it using DAQ features.
    Please give me an example.
    I have found something but I am not sure if it can be used in this way (see the attachment)
    Thank you!
    Solved!
    Go to Solution.
    Attachments:
    DAQ Test write analog+read analog.vi ‏49 KB

    Mcdan wrote:
    Quick correction to my last post... I did not notice that your original VI called DAQmx Start.  In this case I think it is preferred to call start before your loop rather than calling commit, since start will put the tasks in running state outside of the while loop.  In Jeff's proposed change, the tasks would need to transition from committed to running and then back to committed each iteration of the loop.  As originally written, the tasks will be in the running state before the while loop and remain there until they are cleared.
    Dan
    Dan- You missed the Autostart(T)-  and, ALL tasks go from committed to run and back to committed,( unless abnormally terminated by a explicit abort while running starting from a state other than committed,) the commit state is the least overhead for any task that is not continuous or regenerating.  The original post started the task from Verify state- and required DAQmx to reserve and commit the DAQ resources for each read or write and then (since it Started from verify) implictilly uncommit and un reserve the resouce after "running" in each loop iteration.  Sean N "Popped-the-hood" and gave difinitive advice on the DAQmx task state handeler in this post (warning ----wrap head with duct tape before reading) 
    Sorry to derail the thread but, accuracy counts too.  I can't let a user stay stuck behind an "8-ball" with misconceptions (nice avatar by the way)
    Jeff

Maybe you are looking for

  • XML Bursting Issue

    HI All. I get "Error!! Could not deliver the output for Delivery channel:null . Please check the Log for error details" for some POs when I run custom program with bursting enabled. In that regard. 1. My control file is as below. 2. When I checked th

  • SP1 for Windows Server 2008 R2 - Host ok for VmWare Server 2??

    Hello, I am running a VmWare Server 2.02 on a Windows Server 2008 R2 - Host. Are there any known problems with regard to VmWare Server 2 when installing SP1 on the Windwos Server 2008 R2 - Host? I was reluctand to install SP1, because I was unable to

  • Can't create working DVD in Encore CS3

    Hi, I'v created an Encore CS3 project which works perfectly when built to a flash (.swf) and the buttons, menus & videos all works perfectly in the preview in Encore. I've tried burning DVDs two ways: 1. directly from Encore 2. burn an image to my ha

  • Ipad 2 won't turn on or off and is stuck on saying it is still plugged in...help!

    My ipad wouldn't update to the new ios, then lost a lot of my purchased items, and now my ipad is frozen on a screen that says its still connected to itunes when I don't even have it plugged in and my itunes wouldn't even recognize it in the first pl

  • Can you launch an android app from an android app built with air?

    Hi I might a have project coming up soon where one of the requirements is that the android air application can launch another application on the device... In pure java this would look something like this.... Intent LaunchIntent = getPackageManager().