Problem with PWM signal + analog input together !

[marc france]

Hi everyone,

I have attached a very simple VI where I want to :

 1°) acquire a 50 hz PWM signal (I have used one of the Labview examples) to get a value once per second

 2°) acquire 1 analog voltage : 100 samples at a rate of 1KHz every second and then make an average

These to things work fine on their own ! However when I create this VI it works fine for a few seconds and then I get a failure message. I then need to "initialize" the Daq-pad with MAX.

Would anybody know what the pb is and how I can get them to work together? Ideally I would need to measure another PWM signal.Once again I succeed in measuring two pwm signals (with ctr0 and ctr1) but not with the analog signal at the same time.

Am I doing something wrong or is it just perhaps not possible with this card?

Any help would be great,

I am using windows XP, Labview 8.0 and a DAQ-PAD 6015

Thanks,

Marc 

[R_Duval]

Hey Marc.

Could you attach a screenshot of your failure message please? It should be helpful.

Best Regards.

[marc france]

Hi Romain,

Thanks for your help. Here is a screen shot of the message. We can go on in French if you want ( I am French).

Best reagards,

Marc

[marc france]

PS : my screen shot gets clear to read if it saved on the computer and then opened..

[R_Duval]

Hello Marc,

Typically this error is caused by the absence of a clock when performing timed operations.  For example, if you set up a task with an external clock, but then fail to connect the clock signal.  The board will wait and then timeout when it does not see any incoming clock edges.

You are simply performing a test panel, and therefore the clock should be internal to the device.  This may indicate a damaged counter system on your board. We provide a utility to test your card to verify that each of its subsystems are working.  I recommend running the DAQ Diagnostic Utility (DAQmx 7.5 or newer) or E-Series Diagnostic (Traditional/Legacy DAQ) and if possible, testing the card in a second system to verify that the problem lies with the card. If you find the card fails, please request support at ni.com/support to initiate a repair.

Regards.

Message Edité par R_Duval le 01-10-2008 09:31 AM

[marc france]

Hi Romain,

I have tried the DAQ Diagnostic Utility (I have attached the log file) but all the tests are ok. I have tried with another computer but the same fail message appears... the device works fine according to the test result (and according to MAX or when I do these measurements seperatly) so I guess there is something wrong in my program?

If you have another idea...

Thanks,

regards,

Marc 

[R_Duval]

Hi Marc.

In fact, we know that your card is ok .

"Typically this error is caused by the absence of a clock when performing timed operations.  For example, if you set up a task with an external clock, but then fail to connect the clock signal.  The board will wait and then timeout when it does not see any incoming clock edges."

Do you use an external clock?

or configure anything with it?

[marc france]

No I am not using any external clock. I am just running the VI I have posted... so from what I have understood, I am only using internel clocks for the analog input and the PWM signal.  Have you been able to run my VI?

Marc

[R_Duval]

Yeah, I have already run your VI. I hadn't your problem.  

You could reinstall the drivers, but i advice to desinstall them before.

You can dowload the drivers here : https://www.ni.com/en/support/downloads/drivers/download.ni-daq-mx.html

[marc france]

Hi Romain,

Well I had infact already reinstalled Labview 8.0 + the drivers a week ago....

I think I'll just have to acquire my two PWM signals throughLabview and use another solution to measure the analog voltage on its own.

Thank you very much for your help anyway,

Regards,

Marc