Error Code -201002

[bigg_jon]

Hello,

I have a LabVIEW program which configures a timer to use the 80MHz TimeBase as the sample clock source for a 4KHz hardware timed single point counter pulse output.  This worked fine with DAQmx 7.4.  However, after upgrading to DAQmx 8.0, this operation gives error code -201002 (which I couldn't find in help) saying:

"Sample Clock Rate must match the frequency of the internal timebase specified as the Sample Clock Source.

To use the specified Sample Clock Rate, set the Sample Clock Source to OnboardClock.  To use the specified timebase as the Sample Clock, set the Sample Clock Rate to the frequency of that timebase."

So I tried setting the source to OnboardClock, but another error popped up (sorry, I forget the number), and it said I needed to specify an external clock.

The only way I could fix it was to set the timing to Implicit and specify continuous samples.

Does anyone have any experience with this error or some info that may explain why it is occurring with DAQmx 8.0?

Thanks,

Jon

[Justin_M]

Hi Jon,

It looks to me like that was actually an error in the 7.4 driver that wasn't being checked for.  Did that code actually generate the correct pulse train from your DAQ card?

You already figured out the correct way to do it, which is to set the timing to Implicit and choose either Continuous or Finite samples.  I believe the counter will use the 20 MHz counter by default, but you can programmatically set it to use the 80 MHz clock using the channel property node:

Thanks,

Justin M
National Instruments

Message Edited by Justin M. on 04-19-200607:43 PM

Message Edited by Justin M. on 04-19-2006 07:44 PM

[bigg_jon]

Hi Justin,

Thanks for the info.

I kind of inherited this code, so I'm not 100% sure of the actual intention, but the counter internal output (dev1/Ctr0InternalOutput) is then used as the sample clock source for a digital output task.  The counter output is not used "externally" anywhere else.  Is this timing scheme more robust than just using the onboard clock signal?  Anyway, the code executed fine and the test functioned correctly with DAQmx 7.4 with this configuration so I am assuming that the pulse output was correct.  We installed the test exe on several other machines which had DAQmx 8.0 installed and that is when we found the error.  But the implicit timing took care of this and seems to function correctly also.

Thanks again for the information; I appreciate it.

Jon