How to do a simultaneous snap from two GigE cameras?

I have 2 Basler Scout 780-54gm cameras (monochrome GigE) that I am triggering externally at 10 Hz. This frame rate is modest and the resulting data rate is not particularly high. I would like to get images from both cameras from the same trigger pulse. I have an Intel Pro/1000 NIC and I am using the NI driver that shows up as National Instruments GigE Vision Adapter. When I use the Basler Pylon Viewer (the software that comes with the cameras) I can see perfect images from both cameras at the same time at 10 Hz. This tells me that the network, NIC and drivers can handle the data rate with no problem. I have jumbo frames enabled.
  When I try to acquire images into LabVIEW 8.6 with IMAQdx vis, though, I run into problems. I can acquire from each camera alone, but I can't get both at the same time cleanly. The images are shot through with black horizontal lines that appear and move erratically. I have attached a vi that shows the problem. I configure and start both acquisitions, then enter a while loop which reads the images. If I do the acquisitions sequentially by starting and stopping them inside the loop and making sure that one stops before the other starts then I get high-quality images but they are not from the same trigger pulses, and the overhead of starting and stopping the acuisitions slows things down so that I can't get images from every trigger.
  My guess is that this is a problem with the way LabVIEW is managing memory, resulting in corruption with simultaneous acquisitions. Are there any settings I can change to cure this problem? I have experimented with everything that I know about, but no success yet.
Attachments:
Two GigE Grabs standalone.vi ‏50 KB

Hi Richard:
You should put the tick count function in a sequence structure in order to make the loop timing consistent each iteration, but what are you receiving as a loop time?  If it's operating in less than 100ms, it shouldn't be the software that's affecting the images.
One other thing you can try is to get rid of the error wire between your Get Image VIs.  This will keep the program from forcing a delay by executing the functions one at a time.
Alex Person
NI-RIO Product Support Engineer
National Instruments

Similar Messages

  • Simultaneous access from two virtual mashines on one framegrabber

    Hello,
    is it possiblie to get access from two virtual mashines on one framegrabber. I want only get the information from Cam-A  and transfer it to virtual mashine A. For Cam B and virtual mashine B is it similar.
    My problem is that I have to measurements but they have to run at they same time and I want to use the Vision Builder AI for this. If it's right that that  the Vision Builder is able to do only one measurement at the same time.
    Another solution could be, to export the vbai to .vi's and import it to LabVIEW, coundn't be?
    best regards
    phil
     

    As far as I know, virtual machines cannot access plugin frame grabbers. Are you using GigE cameras (which should work in VMs since they can use GigE ports of PC), or CameraLink cameras (which shouldn't work in VMs since they require plugin frame grabbers)? As far as processing images from two different cameras at the same time in VBAI, You can process images that were acquired at the same time in VBAI, but the processing steps don't execute simultaneously. Do you just need the acquisition to be in parallel or the processing as well. Why does the processing need to happen in parallel (is it for timing/perfromance)? If the inspection is running on windows, you can have two instances of VBAI running at the same time and each instance can process a different camera, but it may be more challenging to coordinate the results of the two different inspections if they need to be combined at some point. If you are acquiring on Windows, you could also use the API in LabVIEW to control the two inspections that are happening in parallel and coordinate the results. See the example of how to use the API here:
    \<NI Install directory>\Vision Builder AI 2014\API Examples\LabVIEW Examples
    Hope that helps,
    Brad

  • From two given tables, how do you fetch the values from two columns using values from one column(get values from col.A if col.A is not null and get values from col.B if col.A is null)?

    From two given tables, how do you fetch the values from two columns using values from one column(get values from col.A if col.A is not null and get values from col.B if col.A is null)?

    Hi,
    Use NVL or COALESCE:
    NVL (col_a, col_b)
    Returns col_a if col_a is not NULL; otherwise, it returns col_b.
    Col_a and col_b must have similar (if not identical) datatypes; for example, if col_a is a DATE, then col_b can be another DATE or it can be a TIMESTAMP, but it can't be a VARCHAR2.
    For more about NVL and COALESCE, see the SQL Language manual: http://docs.oracle.com/cd/E11882_01/server.112/e26088/functions119.htm#sthref1310
    I hope this answers your question.
    If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all tables involved, and also post the results you want from that data.
    Explain, using specific examples, how you get those results from that data.
    Always say which version of Oracle you're using (e.g., 11.2.0.2.0).
    See the forum FAQ: https://forums.oracle.com/message/9362002

  • How to Create a new column from two different result sets

    How to Create a new column from two different result sets, both the result set uses the different date dimensions.

    i got solutions for this is apply filters in column formula it self, based on the requirement.

  • HT1449 how do you move all music from two computers into one itunes account?

    How do you move all music from two computers into one itunes account?

    An "iTunes account" is an online account you use for buying music, like a bank account.  An iTunes collection is the media you see when you open iTunes. Which do you mean?
    If it is two computers, it would also help to know where these are located. Are they on the same local network? If they are, try Home Sharing (and you have control of both and you aren't just trying to get music fro your computer to your friend's computer in another state).  If they are not, you'll have to use an external hard drive or flash drive.
    Is this on a PC? Your computer information says Windows but you posted this in the iTunes for Mac forum.

  • How can I tell if signals from two devices are truly synchronised?

    Hi there,
    How does one check that signals from two devices (two separate devices in a single X-series chassis) that should be synchronised actually are?   I am using a PXIe6361 and PXIe4331 on a PXIe-1073, with Labview 2001 SP1 64-bit. All devices are using the Sample Clock from the 4331 device, and an AI Start Trigger, so they should be synchronised.
    I thought that writing the signal data to file and checking the time stamp for each column of data would be the most accurate, but I have been told that timestamps are software created and therefore don't reflect the actual time that the signals were acquired by the hardware.  When I do this, the timestamps vary by up to 150ms which is larger than I expected.
    If I set the x-axis of the waveform graphs (on the GUI) to "Time" then it appears that the first data sample is taken at different times for the two plots (one plot per device).
    If I set the x-axis of the waveform graphs (on the GUI) to "Ignore time stamp" (so that the x-axis just starts from 0 rather than a date-time) then the first data point occurs at "0" for both graphs. However, I'm not sure that this reflects the actual alignment of the signal.
    What is the best way to check if signals collected on different devices in the same chassis are actually synchronised?
    Thanks,
    Claire.

    Hi Lynn,
    Thanks for your help and for sending the demo.
    I understand the concept of how the signals will look if they're not synchronised and your demo shows that nicely. I guess I have been perplexed by someone else telling me that the timestamps in the output file (and following from that I assume timestamps on a waveform graph) do not give an indication of whether signals are synchronised. The reason they gave for this was that the timestamps are manufactured by the software, not the DAQ hardware.  They suggested that I put the setting "ignore waveform timestamps" on my waveform graphs, and then check that both signals come in at the same time (i.e. both start at zero), but I'm not convinced about this. 
    When I use an analog trigger, neither the timestamps in my output file or on the two waveform graphs are synchronised. If I don't use the trigger, then there is far less disparity in the timestamps in the output file. I've attached two output files here, and my VI.
    This is my first attempt to synchronise a voltage module and a strain gauge module on an X-series chassis, so I want to make sure that I'm achieving the best synchronisation that I can, and the difference in behaviour with and without the trigger worries me.
    Thanks,
    Claire.
    Attachments:
    without trigger.txt ‏5 KB
    with trigger.txt ‏6 KB
    Multi-Device Synch-Analog Input-Finite Acq-Analog Start_Claire_wDigitalin_12June2012 PTbridge.vi ‏196 KB

  • I would like to import two different cf cards from two different cameras into the same project/folder and have them be in order of the times they were taken, is there a trick?

    I would like to import two different cf cards from two different cameras into the same project/folder and have them be in the order of the times they were taken, any ideas on how to do this?

    Just import them normally and sort the project by date. They will fall into place. If you tried this and it isn;t happening then make sure the data and times on the two cameras are identical and make sure you are sorting by date and time and nothing else.

  • Receive image from two web-camera​s

    Hallo all.
    I have LV 7.1.1
    I have two web-cameras which are connected to USB1 & USB2.
    How can I see two images  from two web-cameras or more in LV  at the same time?
    With respect
    Aleksandr
    Message Edited by [email protected] on 06-19-2006 01:20 AM

    Aleksandr,
    The IMAQ for USB driver communicates to the 3rd party camera driver using Directshow.  There is an IMAQ USB Property Page VI available in LabVIEW that gives you the ability to open the camera configuration page of the 3rd party camera provided that there is one available.  Depending on the vendor, you may or may not have access to change the resolution of your camera through this property page.   I would contact the manufacturer of the camera to find out if there is a way to do this.
    In case you are curious to know where to find the IMAQ USB Property Page VI, right-click on the block diagram and go to Search in the upper right corner of the palette.  Search for "IMAQ USB Property Page" and the corresponding VI will show up in the list below it.
    Regards,
    Mike T
    National Instruments

  • How do i upload a movie from my panasonic camera to iphoto?

    how do i upload a movie from my panasonic camera to iphoto?

    What format is it?
    You may need to use iMovie
    LN

  • Does anyone know how to remove the fisheye effect from a gopro camera, remove it with premiere pro c

    Does anyone know how to remove the fisheye effect from a gopro camera, remove it with premiere pro cc.

    Use the Lens Distortion effect, set curvature to your liking.

  • I sent some emails from one of my email accounts and now it shows that these emails have been simultaneously sent from two of my email accounts

    I sent a few emails from one of my accounts that are set up in my Thunderbird. Now I see that they have been sent from two of my accounts, simultaneously. It shows them in both Sent folders and with the respective email address as sender.
    Those email accounts have been set up in my Thunderbird for a long time now and have been working correctly until now.
    How can I prevent this from happening again? I don't want to send people messages from two different emails at the same time.
    I'd appreciate any help on this.
    Thanks,
    Borislav

    In my case, TB is sending a copy of all my sent mail to the account that is associated with the smtp server. I have four accounts that I check via TB and the sent mail is being kept in the original folder and also in the sent folder of the account to which the smtp server is connected. If I change the smtp server from one gmail account to another, the sent mail follows. I then have two copies of the sent email, one in the original folder and one in the smtp server account's sent folder. I only want the one in the original folder. How do I stop the sent email from also being saved in the smtp account sent folder?

  • How do I enable opening firefox from two different computers sharing the same home directory without having to delete a lock file (linux).

    I just don't want to have to delete a lock file - which has a purpose - in order to use firefox simultaneously from two locations on the network - where the home directory, i.e. .mozilla directory - is located

    You need to use two separate profiles if you want to have two Firefox instances open at the same time.
    See also http://www.mozilla.org/unix/remote.html

  • How add new column in analysis from two subject area

    which is the right way to add a new column to an existing combined analysis from two subject areas?
    if I add the new column first in my two combined queries, then I saw a new column in the results column panel, but this new column is empty and I can't edit its propreties (the button edit column doesn't work). I can't even save the modified analysis due to a "bad xml" errror.
    if I try to first add a new column from the results panel and then in my combined queries, obiee says that new columns are not of the same type.
    I suppose this is because the new column in results panel has no aggregation formula, unlike new columns in queries.
    But I don't know how to change the properties of the new field in the results panel, with no subject area available.
    I have to restart from a single subject area? possible?
    In this case, there is a way to save/copy filters ecc. from the old analysis?
    If anyone can help.
    Thanks
    Luc

    When you are using union clause in analysis or combining with other subject area you suppose to have same number of columns and their datatypes with other analysis.
    for datatype issues you can use cast in column expression in each analysis. If you want to add a column only from 1 analysis just add and in other analysis use dummy column with exp 0 or ''(for char) based on the datatype.
    These you have to deal with each analysis.
    If helps pls mark

  • How to design universe with tables from two databases using a db link?

    I am building a universe (v3.1) that has tables from two different oracle db instances.  My dba created synonyms for me and there is a database link in place.  I don't know how to get this working in Designer.  I can see the views under my ID when I browse to insert a table, but there is no structure.  I think I have to create a new strategy.  I attempted to do that, but the directions aren't very clear to me, and it isn't working.  Any help or advice would be greatly appreciated.  Thanks!!

    i've been working with DB links much before, but this was since long time ago before i join the Business Intelligence field
    from my understanding that you Have link from DB1 to DB2
    and from your user in DB1 you can access tables and view from DB2
    if you are using your user to create a universe im not sure if you can use tables from DB2 or not
    and you dont see the tables of the link in the Universe
    but you can try to create a drived table selecting from any tables from DB2
    for example
    select id,name from user.table2@mylink
    check this way and give me your feedback
    good luck

  • How to receive mail on iPad from two different addresses

    how to receive e mail on iPad from two different addresses and using these same two addresses receive e mail on computer

    Go to mail in settings and add the new account
    User guides
    http://manuals.info.apple.com/MANUALS/1000/MA1595/en_US/ipad_user_guide.pdf

Maybe you are looking for