topic Re: Continuous buffer with interrupts doesn't refill the buffer in Counter/Timer

Continuous buffer with interrupts doesn't refill the buffer

grivlis — Fri, 03 Nov 2006 16:07:48 GMT

Hi To All,

I'm trying to use a PXI-6602 to acquire 8 channels of event counts. I'd like to use buffered event count at 100Hz, and I know that I have to use interrupts on some of the channels. My problem is that the 3 channels that use DMA work properly but the channels that use interrupts do not refill the buffer in a cicrcular fashion. Except for the configuring some channels for interrupts, the configuration of the channels is identical (and done in a loop). In fact, it doesn't matter which channels I set for DMA and which for interrupts---the DMA ones work and the interrupts do not.

Note that the interrupts one DO fill the buffer one time only. They only seem to be unable to REfill it.

Anyone has any insight?

Thanks,
Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Mon, 06 Nov 2006 16:58:51 GMT

Gil,

Thanks for contacting National Instruments. This is an interesting issue. Are you receiving an error of any kind? What environment are your developing in, i.e. LabVIEW, CVI...? How are you determining that the buffer ids not refilling? I am not sure yet as to why this would happen.

Regards,

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Mon, 06 Nov 2006 18:18:29 GMT

Hi Kenn,

(a) I'm using Visual Studio 2005 and Traditional NI-DAQ 7.4.2f3.
(b) I'm not getting any error.
(c) I use an event callbacks to check the buffers.
To me more detailed, here is what I do: I use a PXI-6533 device to acquire (dummy) data at 100Hz and use its sample clock (on an RTSI line) as the clock for the buffered counters. I assign an event callback to the PXI-6533 for a callback every sample. That way, after the samples are acquired, I get the callback and I can inspect the buffers. I also keep a counter that counts the number of callbacks. That number (modulo the size of a counter's buffer) is also the position of the recently acquired event counts.
In the callback function I inspect the data after the counter index reached the size of the buffer and then I see that the counters that were configured with interrupts do not get refilled. I will try to prepare a sample application and post it (it's a little hard to untangle the code from my current application).

Gil

PS. One of the reasons I am using Traditional NI-DAQ is because I can access the naked buffers directly. I find that the overhead of calling the various read buffer functions is too large. (The other reason for using traditional NI-DAQ is that the latency for event callbacks is much better). G.

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Mon, 06 Nov 2006 18:26:48 GMT

Gil,

Are you doing a read any time during this? Eventually the buffer should fill up and if you aren't reading the samples off you wshould get an error.

An example that I could run on my system and only exhibits the problem at hand would be great and then we could determine if there is a known reason for this or just a bug. Thanks for the quick reply.

Regards,

Message Edited by Kenn N on 11-06-2006 12:35 PM

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Mon, 06 Nov 2006 19:36:54 GMT

Hi Kenn,

I am not reading the buffer using the read buffer command. I access it directly. However, that being said, the DMA-configured channels do refill the buffer just fine and the interrupts ones do not. If I read the manual correctly, the buffer should overwrite itself without an error. It is only the read function that returns error codes if it couldn't read it fast enough.

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Mon, 06 Nov 2006 19:48:40 GMT

Gil,

Yeah that may be true. Is it possible to recreate the issue on a very small scale? So just one counter setup to do do IRQ transfers and see if ti exhibits the same behavior.

Regards,

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Mon, 06 Nov 2006 21:06:01 GMT

Kenn,

I am attaching a VS2005 project that exhibit this behavior. You probably need to modify it to match your hardware device numbers. You can configure it in various ways (just look at the comments in the code).

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Tue, 07 Nov 2006 19:52:15 GMT

Gil,

I got your code. I can't get it to build. I get this error

fatal error LNK1104: cannot open file 'C:\Program.obj'

Any thoughts on what I need to do to get this to run properly.

Regards,

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Tue, 07 Nov 2006 20:05:39 GMT

Hi Kenn,

Hmm. I don't know why it doens't compile. Do you have VS2005?

Anyways, to simplify things, I attach all the code in one file. You can probably compile it with any version of VS by creating an empty console win32 application and adding this file as the only file. (and don't forget to link with nidaq32.lib)

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Jesse_O — Tue, 07 Nov 2006 20:26:10 GMT

Gil,

I created a new win32 console app, linked the nidaq32.lib and included the nidaq.h file location and I still ge the Program error.

Regards,

Kenn N.
Applications Engineering
National Instruments

Message Edited by Jesse O on 11-07-2006 02:33 PM

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Tue, 07 Nov 2006 20:33:22 GMT

That is very curious. I cannot see how you will have a problem just including a source file in your own project. (you shouldn't use any of the previous files I sent, just that single new .cpp file).

Maybe your vs is misconfigured? Try to create a NON empty console win32 app and see if you can compile it. (I mean without any of my code).

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Tue, 07 Nov 2006 21:42:58 GMT

Gil,

I can build a simple win32 console app, but if I add your code and link the nidaq32.lib I get the error. It has something to do wtih spaces being some of the paths. Can you send me the exe itself. My device number is 1. I can run it and verify what you are seeing.

Regards,

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Tue, 07 Nov 2006 21:49:50 GMT

Kenn,

I use two cards, a 6602 and a 6533. Do you have access to both? If you send me the dev nums I'll compile one for you.

Also, try to copy the cpp file I sent into the directory in which you created your empty win32 app, and then add the file. Maybe it will work. I still cannot see where the path name is in my code...

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Tue, 07 Nov 2006 21:53:04 GMT

Gil,

I will make the 6533 be Device 2. How do you want me to add the file?

Regards,

Message Edited by Kenn N on 11-07-2006 03:54 PM

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Tue, 07 Nov 2006 21:59:42 GMT

(1) In visual studio create an empty win32 console application. Call it any name you want. For example we will choose 'ctrtest'.
(2) Copy the single file I send (which I attach to this message again) into the source code directory of the application you've just created.
(3) In VS, right-click the project name in the solution explorer and choose 'add->Existing Item...' and add the file you've just copied into that folder (ctrex.cpp).
(4) Try to compile.

I'll make a an executable as well

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Tue, 07 Nov 2006 22:04:20 GMT

Hi Kenn,

Here is an executable. 6602 is device 1, 6533 is device 2
I packed it in a zip file because the forum's interface doesn't allow .exe files.

Gil

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Tue, 07 Nov 2006 22:06:52 GMT

Gil,

Did that, and if I go to the project properties to link the nidaq32.lib I get the same error. Is there another way to link that file?

Regards,

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Tue, 07 Nov 2006 23:25:40 GMT

Try to copy the nidaq32.lib to your project directory and link against that instead. You probably have a problem with your path.

(Did you tell VS2005 to look at certain directories for you library files? In the link properties in the project properties you should only put nidaq32.lib, and not the whole path. If you use the whole path, try to put quote marks (or maybe double quote marks) around it)

G

Re: Continuous buffer with interrupts doesn't refill the buffer

Kenn_N — Wed, 08 Nov 2006 20:35:54 GMT

DIOCallback 1 (tick 1674878)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 2 (tick 1675038)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 3 (tick 1675198)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 4 (tick 1675359)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 5 (tick 1675519)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 6 (tick 1675679)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 7 (tick 1675839)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 8 (tick 1675999)
        cts:
ct 0: 0, 0, 0, 0, 0, 0, 0, 0
   end: 0, 0, 0, 0, 0, 0, 0, 0

Is this what was expected.

Regards,

Re: Continuous buffer with interrupts doesn't refill the buffer

grivlis — Wed, 08 Nov 2006 21:02:42 GMT

hmm. not really. Is this from the executable I sent, or did you manage to compile to code?

Here is the result that I get (i've modified the code a bit to have a better printout). In this output there are two counters, counter 0 is DMA and counter 1 is interrupts.
The program prints out the conents of the beginning and end of each counter's buffer for the first 10 ticks of the DIO callback (to see that the buffer fills up) and then
also at the ticks around the time the buffer is supposed to get filled up (from tick 252). You can see how the DMA buffer refills and the interrupts one doesn't. You can also see that the counters are working properly, since they count the internal 100kHz source at 100Hz, so each tick we expect the counts to increment by 100 exactly (there is a small drift, becuase the clocks are not synchronized). I attach a new executable with two counters.

DIOCallback 1 (tick 174599125)
counter 0 buffer begining: 274, 0, 0, 0, 0, 0, 0, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 2 (tick 174599125)
counter 0 buffer begining: 274, 1274, 0, 0, 0, 0, 0, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 0, 0, 0, 0, 0, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 3 (tick 174599140)
counter 0 buffer begining: 274, 1274, 2275, 0, 0, 0, 0, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 0, 0, 0, 0, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 4 (tick 174599156)
counter 0 buffer begining: 274, 1274, 2275, 3275, 0, 0, 0, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 0, 0, 0, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 5 (tick 174599156)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 0, 0, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 0, 0, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 6 (tick 174599171)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 0, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 0, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 7 (tick 174599187)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 0
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 0
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 8 (tick 174599187)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 9 (tick 174599203)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 0, 0, 0, 0, 0, 0, 0, 0

DIOCallback 252 (tick 174601625)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 0, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 0, 0, 0, 0

DIOCallback 253 (tick 174601640)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 0, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 0, 0, 0

DIOCallback 254 (tick 174601656)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 0, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 0, 0

DIOCallback 255 (tick 174601656)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 254277, 0
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 254273, 0

DIOCallback 256 (tick 174601671)
counter 0 buffer begining: 274, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 254277, 255277
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 254273, 255273

DIOCallback 257 (tick 174601687)
counter 0 buffer begining: 256277, 1274, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 254277, 255277
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 254273, 255273

DIOCallback 258 (tick 174601687)
counter 0 buffer begining: 256277, 257277, 2275, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 254277, 255277
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 254273, 255273

DIOCallback 259 (tick 174601703)
counter 0 buffer begining: 256277, 257277, 258277, 3275, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 254277, 255277
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 254273, 255273

DIOCallback 260 (tick 174601703)
counter 0 buffer begining: 256277, 257277, 258277, 259277, 4275, 5275, 6275, 7275
counter 0 buffer      end: 248277, 249277, 250277, 251277, 252277, 253277, 254277, 255277
counter 1 buffer begining: 270, 1270, 2271, 3271, 4271, 5271, 6271, 7271
counter 1 buffer      end: 248273, 249273, 250273, 251273, 252273, 253273, 254273, 255273

Gil