Number of DMA Channel on System

I need to log 16 (my be 32 later) simultaneous channel at the same time.
Is the limit of DMA chanels a windows system problem or just a card problem?
I understand that there is a limited number depending on the operating system.
So I cannot use 4 6601E cards (4 chanels each)at the same time on a PC.
I am told my NI that I could us PXI rack with a number of 6115 cards and an embeded controller running Window but I can not see that this would resolve the DMA problem unless it was a modified window system.
The other problem I see is that if Window 2000 or XP configers the cards to use he same chanel, Window will not let you change anything youself as all seeting are allway grayed out.
Judging my the large number of post on DMA perha
ps NI should write a white paper detaiing all the problems.
Thanks in advance fr your help.
Colin

Hello Colin,
Back with the ISA boards the limit of DMA channels was due to the computer itself. Now with PCI, DMA is handled by the PCI board itself. There has to be separate DMA controller hardware for each DMA channel. Our controller chip suppports up to 3 DMA channels. So I wouldn't say that this is a problem really. It's simply what the card offers, similar to the number of counters that is on the board.
There are fewer DMA channels than counters because 1) more DMA controllers would be more expensive, 2) Most applications probably would not require DMA channels for every counter. Interrupts may be sufficient for slower acquisitions or the the counters may be used for pulse generation which also wouldn't require DMA.
I guess I don't know enough abo
ut your application to comment on the 6115 suggestion. The 6115 is an analog simultaneous sampling board, but they only have 2 counters each. Perhaps it was suggested that you acquire this data with analog sampling. The advantage to this is that you can use the same DMA channel for all analog channels being scanned which would probably be a good alternative for your application.
Russell
Applications Engineer
National Instruments
http://www.ni.com/support

Similar Messages

Number of DMA channels

如題，
我手邊有9636/9633兩張卡，
手冊上都是寫Number of DMA channels=5
請問這個數量跟FIFO Target to host DMA是一樣的意思嗎?
因為我設超過3個FIFO Target to host DMA，就會出現錯誤。
還有FPGA的FIFO最大個數是多少?
因為設3個FIFO Target to host DMA+2個FIFO Target scoped
有時候可以過，有時不行，有時程式還會閃退，真是OOXX
附件:
2013-05-30_151309.jpg ‏45 KB

http://www.ni.com/pdf/manuals/372596b.pdf
Number of DMA channels
http://digital.ni.com/public.nsf/allkb/22E2CE79F77B27508625794C00188265
http://digital.ni.com/public.nsf/allkb/470FF5EE8FD677F58625760A007562B9
您的應用為何?

Maximum number of File channels in PI system?

Hi Experts
We are replacing a tool into PI system in my company, and because of this we have to create around 350 File (FTP to Unix Fileshare) Sender/Receiver channels. Already there are 100+ File channels running in production system. Is there a limit for having number of File channels in PI system?
please let us know if there is any parameter to check this limitation or ?
Thanks for your help and quick response on this is appreciated.
Thanks,
Giridhar

Hi Giridhar,
Its more of a design approach than limitations of PI.
There is no limitation of number of channels you create in PI. as a gentleman previously mentioned it might create performance issue as all the channels will be polling at a time to retrieve data.
few suggestions:
1. during design talk to the business team and try scheduling the channels. like every day 3hrs (morning 6am to9am) for few interfaces. and other business in evening 5 to 8 pm. (not everytime a business would be sending data. based on the region and other things they would have a time at which data transmission is high). -- this should be done in Prod only.
2. Keep the size of each message to optimal size 1 to max 5mb so that messages get processed fast.
3. configure the channels very proper with Connection mode : per file transfer .
4. in advanced mode set "ftp.timeout" parameter. this will ensure thread is released one the data transfer is complete/or time exceeds.
5. discuss with the business and set the max file size limit in file sender channel. ...etc
there are many other things you can do to manage large amount of channels (especially file channels) in PI system. this will give optimal performance of PI system overall.
Warm Regards,
Senthilprakash.

X Series DDK: Configure Interrupt on DMA Channel's total transfer count

Hello,
In the DAQ-STC3 X Series DDK Reference Manual, Chapter 1: Theroy of Operation, Section Interrupts, Subsection Special Considerations: Maximizing Throughput in Low-Latency Situations (p41), it is said:
"for X Series devices, the CHInCh can interrupt on the DMA channel’s total transfer count, which occurs once the data has been completely transferred to the host memory. The order of programming for this situation (and output operations) is as follows:
1. Program the DMA channel’s Total_Transfer_Count_Compare_Register (CHTTCCR) with the number of Bytes in a single input/output sample.
2. Set the DMA channel’s Notify on Total Count flag in the CHCR.
3. Set the DMA channel’s Arm Total Count Interrupt flag in the CHOR.
4. Start data transfer (through the DMA controller and the subsystem’s Stream Circuit).
5. Receive total transfer count interrupt.
6. Increase the CHTTCCR by the number of Bytes in a single input/output sample.
7. Re-arm the total transfer count interrupt in the CHOR.
Using the X Series DDK, I don't manage to perform such a configuration.
Can you please provide me code sample to do so ?
Thanks in advance for your support.
Sincerely
Bertrand

Hello Steve,
Weeks ago, we developed a Linux application that configure NI acquisition board (serie X) to send an interrupt when FIFO count reach a given number. At this stage we manage to prove that our board configuration was good and that the problem was due to INtime. TenAsys (INtime developers) fix this issue few weeks ago.
We just come back from holidays, apply the modifications created by TenAsys and manage to get interrupt inside INtime.
We still have two problems.
Reading DMA
===========
From the interrupt handler, when we access to the DMA to get samples stored in the FIFO, we manage to get the samples inside the first interrupt handler. With the following interrupts, when accessing DMA with the tCHInChDMAChannel structure, it said that there is no available bytes. But when we read the Channel_Total_Transfer_Count_Status_Register from the DMA channel, we see that we have the desired numbers of samples.
In the interrupt handler, during the interrupt aknowledgement, instead of only reading the Volatile_Interrupt_Status_Register to ackowledge the interrupt, if I increase the Channel_Total_Transfer_Count_Compare_Register_LSW by a given number (X) then I got X samples to read in the following interrupt. Problem with this solution is that the delay between two interrupts is not constant.
It seems that we mis-configured the DMA channel. But don't manage to find the error.
Two interrupts generated
====================
Moreover, we always get 2 FIFO_Count interrupts. Even configuring conversion, sampling and interrupt frequencies at very low value (conversion 1KHz, sampling 1Hz, interrupt generation: 1Hz). The delay between the two interrupts is about few nano seconds.
Source code
============
I attach to this post the source code we use to play/test this configuration. There is a Visual Studio workspace that we used to play with INtime and a CMake configuration file that we used to manage our Linux tests. You can find all the informations you need to build the binary in the README file.
Thanks in advance for your help with these issues.
Sincerely
Bertrand Cachet
Attachments:
IOMonitoring.zip ‏355 KB

Finite Measure with 2 boards 6602 and 6 DMA Channel Counter Buffered - error 200141

Hi all,
First .. I'm a beginner with LabView and I hope to explane myself in good way cause I'm italian..
I red all the post about the error 200141 and check the suggested solutions (also the way to ignore the error), but I want try to ask for a differet one..
What i'm trying to do is to aquire 6 encoder, 3 on the first board PCI 6602 and 3 encoder on the second board on DMA channels.
The encoder generate 90000 X4 = 360000 pulses x revolution and the max speed rotaion is 4 RPs.
Cause I need to store in a bin file all the pulses from the encoders, i generate a trigger of 1.5 MHz to get all the samples at the max system speed (360000 * 4 = 1440000 pulses x sec).
I think to have reached the limit, and maybe is not possible do better.. actually the 2 PCI 6602 works with 1,0 MHz of trigger and the system store in 6 files 4000000 of samples during
the finite measure of the angular position on 6 channels.
The trigger is not yet sync between the 2 PCI cause I'm waiting for a RTSI cable to put in the PC...
In Your opinion is possible to find a alternative way to acquire these encoders ?..
Thanks

I also doubt if you need to capture every single increment from each encoder. I'll discuss this more below.
Further, many earlier discussions suggest that counter tasks can sustain data transfers merely in the 100's of kHz, with *maybe* a possibility under special circumstances to slightly exceed 1 MHz. Your boards have very small hardware buffers (either 1 or 2 samples worth), causing the PCI bus usage to be very frequent and therefore less efficient.
Now, let's go back to your sample rate. You've got encoders which suggests that you're dealing with a physical system. Physical systems have inertia, which limits their useful bandwidth. In my experience, it's quite unusual to care about motion artifacts beyond the 10's of kHz. The inertia just doesn't allow anything significant to happen at that rate.
So, if the physical bandwidth of your motion system is, say, 5 kHz, there's a rule of thumb suggesting to measure at 10x when possible. So that'd mean 50 kHz sampling. 50 kHz x 6 channels on the PCI bus may be possible. Multi-MHz sampling won't be.
Can you describe the physical system a bit?
-Kevin P.

How many DMA Channels does my device have?

I would like to know how I can find out (progammatically) how many DMA channels my device has. I am using the DAQmx driver. Other than with the traditional DAQ I can't find out anything about my device but the "type" and the "serial number". Where can I get some more details about the device (not in the MAX - I want to know it in my program) with DAQmx?
My intention is to find out how many DMA Channels the device has and depending on how many Channels I need - I am using "interrupts" instead of DMA.
Somewhere in the KB of Ni was written that the NI-DAQ 6.9.... realizes automatically how many DMA Channels are available and how many I would need - and so he takes "interrupts" for the rest.
It seems that they did a "step bac
kwards" because with the NI-DAQ 7.2 it doesn't work automatically if I need DAQmx VI's.
Does somebody know anything that would help me to solve this problem?
Thanks.

Sorry! I posted my first revision of the answer.
Here is what I meant to say:
Hello,
According to this KnowledgeBase, DAQmx and Traditional DAQ behave the same. Are you seeing something different?
As far as a workaround goes, all you have to do is trap the No DMA error. This error should be -200251. So in software, if you receive error -200251, then you need to configure the board to use interrupts, and then start the task again.
How to configure the board for interrupts differs from the four different DAQmx API�s (C, C++, DotNET, and LabVIEW). If you are unclear about how to do this in your environment, please let us know, and we can find
out.
Best regards,
Justin T.
National Instruments

1BS: N number of Communicatio channel

i am having 15 scenarios..
can i use one business service and n number of Communication channels under it.

Hay Aamir,
here they are using Business service for IDOC and proxy...can they use that....
it is not form one system...different systems...but one business process....
I mean 12 interfaces belongs to one business process..
almost 8 are same system and the rest are different..
they want me to go with one business process for all the 12 interfaces...
shall we go
Edited by: PSRK on Jul 25, 2008 3:31 PM

Elite plus account online says my phone number is not in the system...

Hello,
I have been a member for many years, and have pretty much always used the same phone number when accessing the myrewardzone.com and at the store to apply the purchase. However recently, when accessing the mybestbuy website, there is a notice to enter my phone number for verification to check points. When doing so, it says that number is not in the system. I just went a best buy store yesterday and purchased a TV using that number and it went through fine.
Is there anyone who can help with this?
Thank you!
-John

Good morning jedimario,
I hope you are having a good start to your weekend.
I am the who, and from what I can see, you have quite a bit of unnecessary information on file (phone #s, mailing addresses, and email addresses). I would strongly suggest that we update your information and get it down to three primary pieces. Please send me a private message with the below information, by clicking on the blue button in my signature, and I will make sure everything is up-to-date.
As far as your points, you should receive a 25% bonus for having Elite Plus status. I looked over your points history and show that you have in-fact been receiving the bonus points. You may not see those bonus points pending for recent purchases because it is fairly common for bonus points not to appear as pending, but they should post to your account within 20 days of the original purchase date.
Name
Phone #
Mailing address
Email address
Thank you for reaching out to us on the forum!
Derek|Social Media Specialist | Best Buy® Corporate
Private Message

How do I reduce the number of audio channels in the source or export settings?

I'. trying to export my finished edit through the "movie" setting but keep getting the message that the number of audio channels to create in the exported file must be equal to, or less than the number of channels in the source. Reduce the number of audio channels in the source. Reduce the number of audio channels in the export settings. I am at a loss as to what this means and how I proceed with it prior to putting it to DVD. Please advise.
JWooley

What is your source, sequence settings and export setting. Which version of PP?
Prefebly a screendump of the export settings box.
(e.g. trying to export a mono track to 5.1)

Dma channel problems

Hello,
I really need help on this one. Using PCI-6035E I am trying to output an analog signal (actually 2 waverforms interleaved together) on 2 channels while simultaneously using the two GPCTRs to measure two separate signals' pulse widths. The VI runs perfectly on some occasions, while on others I get "no DMA channel available for use". Whenever this message appears and I try to exit labview, the nipalk.sys driver messes up and I get a blue screen crash that says "process_has_locked_pages" (I traced the locked pages to this driver). I've tested this many times and it appears to me to be totally random. I've used the Set DAQ device information VI to set the two counters to use interrupts, but I need to use the one DMA channel for
the analog output. My best guess is that there is some kind of resource conflict with something else in the PC, but I can't figure out how to change DMA assignments(I'm using Windows XP). The NI-DAQ Measurement and Automation Explorer tells me that the card is using DMA 0, IRQ 17. I've tried uninstalling all the NI-DAQ drivers, reinstalling and updating. Any help anybody could give me would be greatly appreciated.
Thanks,
Nick
Attachments:
aug7.vi ‏374 KB

Hello;
The PCI bus has 3 DMA channels that are share in between all devices that do DMA data transfers.There is nothing you can do to change that, since that is a PCI bus feature.
The best way to go about that is to remove other devices that use DMA, such as network cards, for instance. That might free up more DMA access time for your DAQ device to execute its data trasnfers.
Hope this helps.
Filipe A.
Applications Engineer
National Instruments

WSUS Sync is not working Sync failed: UssCommunicationError: WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. --- System.Security.Authentication.AuthenticationException: The remote

I know there are loads of posts with same issue and most of them were related to proxy and connectivity .
This was case for me as well (few months back). Now the same error is back. But I've confirmed that FW ports and proxy are fine this time around.
server is configured on http port 80
ERROR
Sync failed: UssCommunicationError: WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid
according to the validation procedure.~~at System.Web.Services.Protocols.WebClientProtocol.GetWebResponse(WebRequest request). Source: Microsoft.SystemsManagementServer.SoftwareUpdatesManagement.WSyncAction.WSyncAction.SyncWSUS
I've checked proxy server connectivity. I'm able browse following site from WSUS server
http://catalog.update.microsoft.com/v7/site/Home.aspx?sku=wsus&version=3.2.7600.226&protocol=1.8
I did telnet proxy server on the particular port (8080) and that is also fine.
I've doubt on certificates, any idea which are the certificates which we need to look? And if certificate is expired then (my guess) we won't be able open the above mentioned windows update catalog site?
Any tips appreciated !
Anoop C Nair (My Blog www.AnoopCNair.com)
- Twitter @anoopmannur -
FaceBook Forum For SCCM

Hi Lawrence ! - Many thanks for looking into this thread and replying. Appreciate your help.
Your reply ("SSL is enabled/configured, and the certificate being used is invalid
(or the cert does not exist or cannot be obtained), or the SSL connection could not be established.") is very helpful.
I've already tested CONTENT DOWNLOAD and it's working fine. WSUS Sync was also working fine for years with proxy server configured on port (8080) and WSUS server on port 80.
My Guess (this is my best guess ;)) is this something to do with Firewall or Proxy side configuration rather than WSUS. However, I'm not finding a way to prove this to proxy/firewall team. From their perspective all the required port communication open and
proxy server is also reachable. More over we're able to access internet (Microsoft Update Catalog site) over same port (8080).
Any other hints where I can prove them it's a sure shot problem from their side.
Thanks again !!
Anoop C Nair (My Blog www.AnoopCNair.com)
- Twitter @anoopmannur -
FaceBook Forum For SCCM

I have this problem,    Tag 'A2B0': Number of input channels is not correct.     Tag 'A2B0': Number of output channels is not correct.     Tag 'B2A0': Number of input channels is not correct.     Tag 'B2A0': Number of output channels is not correct.

i have this problem,
Tag 'A2B0': Number of input channels is not correct.
Tag 'A2B0': Number of output channels is not correct.
Tag 'B2A0': Number of input channels is not correct.
Tag 'B2A0': Number of output channels is not correct.
I work with Capture One Pro 7, photo editor
what can I do to solve this problem?

You may have better luck asking your question here: Capture One 7.x Software for Mac
OT

Freeing DMA channels

I am using pattern gen. single buf. input on a 6533 with Win2k and Borland C++ v5. When the program using the board (via NI-DAQ, the latest version) dies badly, it does not seem to free the DMA channel that the board is using. I get the "No DMA channel available for use" error when I run my program again. This means that I have to reboot.
How can I free the DMA channel used by the 6533 without rebooting? I have tried to use DIG_Block_Clear at the start of my program, but it complains that no transfer is in progress.

DAQ_Clear is for DAQ devices, not DIO devices. I get an error -10403 "Device does not support the requested action" when I try this function.
BTW: I mistankenly said I had a 6533; I actually have a PCI-DIO-32HS (they are pretty much the same thing, the 32HS uses PCI instead of PXI).

Determine number of selected channels for traditional DAQ

The blocks of "DAQmx Task" and "traditional DAQ Channel" look quite similar (see attachments). The DAQmx block ist an individual selection of channels and I am able to determine the number of selected channels.
Now I am trying to determine the number of selected channels of a traditional DAQ, but the DAQmx property block does not work here. I did already try some blocks form the trad. DAQ palette but failed.
Any idea?
Message Edited by pgraebel on 07-21-2009 11:31 AM
Solved!
Go to Solution.
Attachments:
DAQ.png ‏2 KB
DAQ_frontpanel.png ‏5 KB

The new attachment is showing channels for traditional DAQ (upper) and DAQmx (lower). You can clearly see a selection of channels inside the traditional DAQ box.
How do I determine the number of channels? The DAQmx way to do that does not work for the traditional.
Attachments:
Clipboard01.png ‏2 KB

How To Configure Videos To Expand Stereo On a 6 Channel Audio System?

I Have A 6 Channel Audio System , I know You tube Supports Stereo Only, but that's not my problem, my problem is that i had just reinstalled my OS, and now only my Front Speakers works while Playing Videos on You tube or any other Internet Stream.Please Help.

"DTV box may not have formatted properly" --> I'd suspect something like that too...
FAT32 is limited to file size of 4GB actually (minus one byte).
In my experience you can copy a larger file to a FAT32 volume, let's say a video file, but when the copying process is finished, you notice the size is 4GB, and when you play the video it ends abruptly at this point.
(another limit is limited file name length and limited use of characters in the filename. A slash for instance is not allowed.)
Piero, did you try to connect your flash drive to a windows machine?

Number of DMA Channel on System

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