Daqmx timing source issue

I have attached zip containing 2 folders. Both are doing same functionality but one using software timed 50ms loop. the other one is hardware based timing source.
I run , quit & re-run the application. Both the applications works well. But the ISSUE folder containg application hardware timing sourced app, after quit, the EXE process keeps running in the background & needs to be stopped using Ctrl+Alt+Del invoking the task manager.
As many times I click on to run the app, it works ok only, but holding the EXE process in background.
Hope someone helps to resolve this. Im using LV2009 + PCI 6229.
Thanks,
Kousy
Attachments:
LV Exec Process Termination Issue.zip ‏1948 KB

Hi,
I found the solution to the problem: using the latest NI-DAQmx drivers v.8.0.
It was directly related to my M-series card (PXI 6221) not correctly working in my PXI chassis due to apparently bad drivers or a bug in version 7.5.
Christoph

Similar Messages

Strange DAQmx Timing Source Timed Loop Error

I have a digital edge counter fed into a timed loop. Everything works fine until I stop the loop, and stop the DAQ task. Once I restart the loop it fails with "resource is reserved". Attached is my code.
Thanks
Solved!
Go to Solution.
Attachments:
daqloop.JPG ‏136 KB

Here is a piece of code to illustrate the issue. If the timing source is created in the loop (it will be created each loop iteration) the error occurs. If it is moved outside the loop, and only created once the issue is resolved. Is there a way to RELEASE the timing source so that it can be created again? If the VI is stopped, this "resource" is released. I want to programatically release it.
Note the error comes from the timed loop Error terminal that is Probed (50).
Message Edited by bkb on 10-08-2008 09:52 AM
Message Edited by bkb on 10-08-2008 09:53 AM
Attachments:
ts.jpg ‏57 KB

[DAQmx] How to delete a timing source ?

Everything is in the title.
I created a timing source in my application, used for defining a hardware frequency control of a timing loop. The problem is that I did not found any VI to delete it, as I would need to modify its parameters.
Is there a way to clear a timing source ?

I did the modification that proposed Albert : I modified the VI that creates the timing source for having the task out parameter. To avoid problems for deployment, I saved the file into the project with a new name.
When clearing the corresponding task, the timing source can be created again, with possibly new parameters. So it works now as expected.
About Kevin proposal, I also checked that, but it seems that all properties are "read only" . Automatic clear of DAQmx task as proposed by Stuart seems to be done only when the application exits, and I do not want to do that on my RT application (to restart the exe, I think I have no other choice than rebooting, and moreover I have a TCP connection with a remote computer that I cannot close).
Well, it would be nice that future version of "DAQmx create timing source" using physical counter also inlcudes this task out terminal, or a dedicated VI able to clear the timing source using its name for example.

Timed Loop timing source - Control Loop From Task is too slow

I'm trying to make a Timed Loop run at a period of 2 ms, with an analog input task running at 50 kHz as timing source. The input analog signal is scaled and fed into a synchronised analog output task on the same multifunction DAQ board. Using the built-in 1 kHz or 1 MHz clock as timing source for the Timed Loop works great, except for a slight time lag between the loop and my AI/AO tasks which over time becomes unacceptable because my task will be running for up to an hour. However, when I use the DAQmx Create Timing Source: Control Loop From Task vi to create a timing source, everything slows down and the fastest loop time I can get is around 20 ms. Any suggestions to get around this would be highly appreciated!
System: LabVIEW RT 8.0 with DAQmx 8.0 running on an NI PXI-8186; NI PXI-6251 used for analog input.

You're welcome!
You can build an array, and if your data is not hugh (100's of MB) this may be the easiest solution. However, we aways suggest implementing the Producer/Consumer Architecture. Keep the PID in the Producer loop, but move the File IO to the Consumer. Also, it appears that your instrument uses some form of serial communication, so that could cause lags in your system....
What is your application about in general, what performance are you hoping for, etc?
Joshua B.
National Instruments
NI Services
NI Support Resources
NI Training Resources

Create Timing Source problem in RT deterministic loop

I'm updating an old LV 7.1 vi to run with LV10 and DAQmx. We have a deterministic timed loop driven by an external 10 kHz clock source. As I understand, it should be possible to set up this functionality using a timed loop and the DAQmx Create Timing Souce vi. The attached image shows how I wired it up.
This vi is deployed to a PXI system running LV 2010 with 6608 system timing card (Dev 1). I'm using counter 1 on the 6608 to create the timing source. I have an external 10 kHz square wave (5 V p-p) connected to Src1 (PFI35) on Dev 1.
The problem: the loop seems to be using a 1 kHz clock, even though I've specified the counter and input for a 10 kHz source. If I choose a frequency of 20 Hz (500 edge counts for a 10 kHz clock) the actual loop frequency is only 2 Hz. But, the loop stops if I disconnect the 10kHz signal, so it is somehow using the specified counter !!?? How can this be? Is there additional counter configuration needed here?? I've verified the external clock signal is exactly 10kHz with an oscilloscope.
Thanks for any thoughts.
Solved!
Go to Solution.
Attachments:
CreateTimingSourceTest.JPG ‏37 KB

OK. I solved this one. You need to wire a "1" constant to the period input node of the timed loop. The default value of "10" will only execute the loop on every 10th clock pulse, hence the factor of 10 decrease in loop frequency.

DAQmx Timing

Dear all,
I have this following VI solution that stems from the LabVIEW example for Continuous Digital Data Output. The issue concerns the System Clock - when set to a low sampling rate value (say, 1S/s), the rate seems to be much higher. The LED indicator on my BNC2120 is dimmed throughout; indicating fast switching between the Low and High?
How shall I edit the enclosed VI to actually write one sample per second? I am using the PXI-6132 card.
Thanks in advance.
Solved!
Go to Solution.
Attachments:
Digital - Continuous Output.vi ‏58 KB

Ok, when you set the clock to use the 100kHz clock, you will be sampling at the 100kHz. I am a little surpised that it won't let you use the onboard clock. Maybe the DIO can only be clocked out with an external clock?
Some tweaks you should make here:
If using an external clock, the rate should be set to the maximum expected rate of that clock. The data will be clocked out based on that clock though.
Since you are using Continuous mode, do not wire up the Samples Per Channel to the DAQmx Timing VI. All you are doing is limiting your buffer size.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Timed sequence doesn't work right with external timing source

I'll describe first what I want to accomplish and
then maybe someone can read further and suggest why the attached VI
doesn't work. I have a SMU (PXI 4130) that takes differing amounts of
time to set a current depending on if the setting spans a range
boundary. I want to be able to make that SMU setting and then wait a
specific amount of time (sometimes 1 msec). If the SMU takes a little
longer to return then I want that extra time to come out of the wait
time. To do this I figured I would need an external time source to
control a timed sequence to give better than the normal 1 msec
resolution. So now onto the problems I'm having.
I've
got two problems here that I would really appreciate some insight on.
The attached VI is the subject of both problems (as is the VI is
worthless, but it illustrates the problem). Note that you need some
type of DAQ board with a counter on it to run it.
I can't
figure out why this timed sequence doesn't work with an external timing
source. It works mostly as expected (see next problem) with the
internal source, but fails miserably with the external source. Run the
VI as is to get a baseline. Then connect the DAQmx Create Timing Source
VI to the Source Name input of the timed structure. It seems like it
should run exactly the same both ways.
Problem 2 (run with the
internal timing source). The VI should take the same amount of time to
execute regardless of the input to the Wait VI (within reason of
course). That's actually the main impetus for this whole exercise. But
according to the Actual End indicator it runs faster with a longer wait
time.
George
Attachments:
test timed sequence.vi ‏144 KB

Hi George, I have been playing with the code that you have posted and I think I am seeing what your concern is with regards to the first problem that you stated. Without running the code I would expect both internal and external timing to cause the VI to run in the exact same manner, however obviously that is not the case. I am currently looking into this behavior and I will post you a response as soon as I have an answer for you.
As for the second problem, If you look at the manner in which you have coded this VI, a 1ms wait in the first frame will lead to a calculation of 1999ms wait in the second frame, and thus 5 iterations of 1999ms or about 99,995ms total running time. If you increase the wait in the first frame to say 50ms, then an overall all wait of 1950ms is calculated in the second frame so not the overall iteration time is now 1950 which, over 5 iteration leads to 99,750ms thus as you increase the wait in the first loop the overall loop duration will be less. This is expected behavior.
Again I will post back once I have a clarification on the internal vs external timing.
Chris_K
National Instruments
Applications Engineer

Timed out issue in jsp page!

Dears,
It is really amazing for me to see this issue in my application which I deployed in Oracle Application Server 10g r2.
I am using JDeveloper 10g to create jsp pages.
On one jsp page i am displaying 15 html tables for a report.
All tables have 1 query to get records from oracle 10g database.
Am opening one connection and than one by one running queries just before each table and rendering data through ResultSet
(which is scrollable).
If I test this page from JDeveloper, it is displaying fine.
But when I deploy this page in Oracle Application Server 10g,
and create a portlet and show this jsp page in portlet and open this page,
this page most of the time giving 'TIMED OUT', and a few times displaying report properly.
I tried PreparedStatement to run multiple queries for Oracle DB, but couldn't make it successfully.
BTW,
I checked my OAS log, it shows following error:
09/03/16 18:39:08 hrwfapp: [instance=(null), id=(null)] ERROR: Request has exceeded its warning timeout Time[elapsed=61046ms.
Warning timeout=20000ms.] Request[id=5003532663665,3 providerId=493501 portletId=117 portletName=AttritionReports
portletInstance=35555_ATTRITIONREPORTS_493501 user=PUBLIC] Thread[ name=AJPRequestHandler-ApplicationServerThread-6
priority=5 alive=true interrupted=false groupName=ApplicationServerThreadGroup]
Please help me in this regard, what should I do to avoid Timed out issue.
Best Regards

Hi,
if this occurs only in combination with portlets then I would try the Oracle Portal forum for help or use customer support to help you analyzing the issue
Frank

When starting the Add-on: Connection timed out issue

When starting the Add-on: Connection timed out issue
Hi,
We have a client in SAP 2005 PL 44.
I built the add-on for them using simple installer wizard ( I tried advanced set-up also).
When starting the add-on, I get the message 'Connection Timed Out'.
Add-on status is failed.
But the add-on is actually connected. i.e, The functionality associated with the add-on is working fine.
I had SAP 2007 before and un/reinstalled SAP 2005 in order to connect with this client.
I had built the same add-on in a similar way for the same client for lot many times in the past, but I never got this issue.
I tried the following:
1) Delete SM_OBS_DLL and un/reinstall DI API
2) un/reinstall B1DE
Always I'm getting this error.
Please let me know your inputs.
Thanks.
Geetha

Hi Geetha,
The timeout issue has been discussed quite a bit already on this forum. Please do a search or look at these threads:
Timed Out Error with ADDON
Addon Connection Timed out
Regards
Aravind

DAQmx Timing (On Demand).vi

Hi!
I am doing a work that uses Cyclic Voltammetry technics. I am trying to use the example from this page "Measuring Cyclic Voltammetry for DAQmx" with a NI USB-6009 card and NI DAQmx drivers.
The problem is that, when I try to run the file appears this error:
Error -200077 occurred at Property Node DAQmx Timing (arg 1) in DAQmx Timing (Sample Clock).vi:2->cv_scan->cv.vi
Possible reason(s):
Requested value is not a supported value for this property.
Property: SampTimingType
You Have Requested: Sample Clock
You Can Select: On Demand
Task Name: _unnamedTask<2>
I know that the USB-6009 only support the On Demmand but the problem is that this type of timming is not present for choose! How can I find it? I think I miss the file "DAQmx Timing (On Demand).vi", or something like that!
Thank you for helping!

Hello AlexandreFSilva,
    This is my first reply so bare with me. I have used the USB-6009 and to aquire analog input either create a global channel or task in MAX or create a Task or access a physical channel directly in Labview. If you create a task for multi channel DAQ the timing should be set by defualt to ON Demand. Once this is done just dropp a Task or Channel constant or control on your block diagram and an Ai Read function inside a loop. The timing for the On Demand DAQ will be controlled by the WAIT value that you place inside the loop. From what I get from your question it sounds like your creating everyting in Labview and using the Timing Function before you start your actual DAQ. The Timing Function is not needed when using On Demand DAQ timing that is why it is not an option. Block Diagram Flow listed below:
Global Channel created in MAX:
    Channel Constant or Control --> Loop --> AI Read --> after loop --> Stop Task --> Clear Task
Physical Channel Accessed in Labview:
    Physical Channel Constant or Control --> Create Task/Channel --> Start Task --> Loop --> AI Read
             --> after loop --> Stop Task --> Clear Task
The Stop and Clear Task are not needed for the Global Channel that you created in MAX and will not throw any errors if left out but is good code to implament. The flow that I listed was pulled out of my head so forgive me if it is slightly off. Simply stated though, you do not need to include the Task Timing Function in your code and if you remove it everything should work properly. Don't forget a WAIT function in your loop, one sample will be read for every value of the WAIT statement.
Goodluck and I hope I did not make things any more complicated or confusing.
Steven.

DAQmx Timing (sample clock).vi

do u know what is the critaria to use DAQmx Timing sample clock.vi... or in what situations this vi must b used?

Hi Pritam,
Thank you for posting on the National Instruments forums.
The DAQmx Timing.VI is used when you need to perform an operation that requries sample timing whether it's Analog Input, Analog Output or Digital IO.
Here is a Developer Zone Article that explains how the Sample Timing VI can be used: Learn 10 Functions in DAQmx and Handle 80% of Your Data Acquisition Applications.
Hopefully this will tell you what you need to know.
Thank You,
Nick F.
Applications Engineer

DAQmx Timing rate

I am using the DAQmx Timing control in a VI that samples data from a PXI chasis. The sampling mode is set to Finite Samples. The help states that the rate input specifies the sampling rate in samples per channel per second. Increasing this number means more samples per second. It seems to me that increasing the samples per second should reduce the overal time of the process since it is performing more actions per second. However, increasing the rate decreases the loop time of my program. What am I missing here? Am I understanding this wrong, or just implementing this strangely?

Hello,
You are right that increasing the rate means more samples per second.
It means the following: If you keep the finite number of samples to
acquire fix, then increasing the rate should decrease your acquisition
time. Suppose you are performing acquisition in a loop. If the
acquisition time decreases, then the time for a loop iteration will
decrease as well.
For example, for an acquisition of 1Hz, if the number of samples to
acquire (on the timing VI) is 1000, it means that you will acquire a
total of 1000 Samples. Since the rate is 1Hz, it will take you 1000
seconds to acquire all the samples. However, in a loop, you can use the
DAQmx Read VI to read part of the total number of samples already
available. So for example, if you specify 50 samples to read on the
DAQmx VI, every time it is called, it will grab 50 samples from the
buffer. If the samples are not available yet, it will wait until they
are availble or there is timeout and return. Now if you have a
process in the loop that take more than 50 seconds to comple before you
read again, then there will always be at least 50 samples in the buffer
from the second iteration. From there on, if you increase the rate, it
will just increase the number of samples availble to be read, but it
will not necessary make the other process in the loop faster. So the
DAQmx Read will always have the 50 samples it needs, but the other
process will still take time. So in this case, changing the rate from
1Hz to 100Hz will seem to have no effect on the entire process.
The important thing is to understand what those numbers actually mean.
-Sample per channel in the timing VI represents the total number
of samples to be acquired by the board on each channel of the task.
-Rate represents the rate at which the samples above are acquired
-Sample per channel in the DAQmxRead VI represents the number of
samples you want the VI to grab from the buffer. Those samples
have already been acquired and stored on the computer.
Hope this clears it all

In the DAQmx Timing VI, if the Cont. Sampling is on...?

Hi!
Can someone please explain to me what happens if:
in the DAQmx Timing VI, when the continuous sampling is on.. but you are asing for samples per channel? This is found in the KnowledgeBase example:
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/3296ba2aef586b7386256d6d00528e3d?OpenDocument

If I understand you question correctly what continous sampling means is that the program will continously make reads what samples per channel specifies the number of samples it will make per read and then put in the buffer. Quoted from the help file..
"samples per channel specifies the number of samples to acquire or generate for each channel in the task if sample mode is Finite Samples. If sample mode is Continuous Samples, NI-DAQmx uses this value to determine the buffer size."
Let me know if you need more explanation. Have a great day.
Allan S.
Applications Engineering
National Instruments

Using Signal Express VI for DAQmx, timing & file size issues

I am using a Signal Express VI with my DAQmx. Long story short, my DAQmx VI's don't work in LV 8.6 (possibly IT installation error). I have a few issues (I'm a beginner so be easy).
First, I'm confused on how to get the timing correct. I am trying to read a 100 samples (2 channels) average them and repeat this at 30Hz and record this data.
Second, everytime I open the Signal Express VI (in my block diagram) and change sampling for example, click OK, then save my VI before running my program. I noticed the file on disk increased in size by the megabytes! All I changed were the sampling settings.
I appreciate any input, thanks in advance!
-Michal
Attachments:
Philtec_09-22-09.vi ‏2589 KB

To your first concern, it sounds like DAQmx was installed before LabVIEW. Just reinstall DAQmx and it will work fine in LabVIEW.
For you second concern. To get 100 Samples at 30 Hz, you will need to change your channel setup in signal express. You will need Continuous Aquisition, with 100 Samples to Read at 3000 Hz. Then you code should work as expected.
Chris Bakker
National Instruments
Applications Engineer
Check out LabVIEW 2009 and the New X-series DAQ!

Does not join to any fact source issue in 10g

HI,
I am getting below issue while compiling rpd.
Logical Dimension Table Dim-XX has a source xx_aa that does not join to any fact source.
Let me describe situation here.
In physical layer , i have one xx_v table . there is no join condition physical layer. But in BMM layer we have created two logical tables for single xx_v table and providing join in bmm layer. When am compiling it i'm getting an error.
The one which i have using current rpd, same rpd in production with out any warnings(Logical Dimension Table Dim-XX has a source xx_aa that does not join to any fact source) and they don't have any logical level mapping in content tab. But i am using same rpd in dev instance getting warnings.
Thanks,
Mal
Edited by: user10675696 on Feb 11, 2013 3:08 AM

Hi Srini,
Please find the below warning here and we don't have an hierarchy for MTL_SYSTE_ITEMS_B
[39008] Logical dimension table Mtl System Items B has a source MTL_SYSTEM_ITEMS_B that does not join to any fact source.
I am getting this in Dev instance only but not in Production. But one rpd can be used in dev and production instances.
Thanks,
Mall

Daqmx timing source issue

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