05-04-2006 08:10 AM
05-05-2006 12:31 AM
05-05-2006 01:20 AM
Hi Thomas,
One small suggestion.
Since trad daq and DAQmx codes seem to access the same Hardware there might be a clash happenning,
are you getting any error msg in DAQmx??
Just try this.
whenever u run trad daq and then go to DAQ mx, use the trad DAQ "Device Reset.VI" for that device and then, execute DAQmx code on that hardware.
Hope this helps
Regards
Dev
05-05-2006 02:49 AM
05-10-2006 02:49 PM
Hi Thomas-
It looks like the DAQmx portion of your code may have a few issues. In MotordrehzahlVorgeben_MX.vi you configure your task for a finite generation of 500 points, but you only write a single point to the task buffer. When I run this portion of the code I receive error -200609 from the DAQmx Write VI.
I would expect you to receive the same error in your app, and it may explain why you're not seeing the output pattern you specify. If you only need to update a single value, simply remove the DAQmx Timing VI and structure your code similarly to the DAQmx LabVIEW example "Gen Voltage Update.vi"
Hopefully this helps-
05-11-2006 12:05 AM
Thanks for this input - I'll give it a try.
I'm not used to DAQmx yet, so I obviously made something wrong - or at least I did not understand the instructions (I downloaded some information about how to change from traditional DAQ to DAQmx) correctly.
Thomas
05-11-2006 09:12 AM
Hi Thomas-
Sounds good- let us know if you run into any other problems.
Thanks-
05-17-2006 04:35 AM
Hi Tom
As I said, I now changed from LV6.1 to LV8.0 on the second testrig. The changes you mentioned (writing a value to the DAQ card) worked but I have a new problem.
Have a look at Drehmoment_Caller.vi. There I load the vi to control the card either with DAQmx or traditional DAQ. I don't know why, but with DAQmx I don't get correct measurements. Do you have more tips which could make this DAQmx stuff work properly?
Thomas
05-19-2006 09:39 AM
Hi Thomas-
Can you please clarify what you mean when you say you don't get correct measurements? Are the readings you receive inaccurate, or do you not receive readings at all? If you are not receiving any readings (or are receiving very few) I would guess that it is because the For loop in your DAQmx subVI is executing too rapidly to allow for any samples to be acquired. The root cause of this is that your Samples to Read input to the DAQmx Read VI is "-1". This tells DAQmx to read all available samples, and if there are zero available then you will return an empty array. I would suggest that you specify a non-zero number of samples to read with each iteration of the loop that is appropriate for the number of samples that you expect for the entire operation. If this is not the problem, please clarify exactly what problems you are experiencing.
Thanks-
05-22-2006 12:16 AM