finite puls train in loop with Hardware timed single point RT

[raisch]

Hello,

i looking for a method for generat a finite puls train in a loop which aquire analog input with hardware time single point. I'm using labview rt on a PXI 6251.

Thanks!

[Marian_O]

Hello Raisch,

thank you for posting at the National Instruments Board. Please clarify, what you are planning to do:

Do you like to generate a finit pulse train or do you want to acquire data from the analog in?

For generating a finit pulse train, you need both (!) counter-units from your NI PXI-6251: one which generates the pulses, the other one, who counts the number of periods and stops the generation.

You find a simple example in the LabVIEW Example Finder (Help » Example Finder). Please navigate inside the Example Finder to:

Hardware Input and Output » DAQmx » Generating Digital Pulses » Gen Dig Pulse Train-Finite.vi

If you like to acquire analog data from your analog inputs using an external clock, please take a look to this example:

Hardware Input and Output » DAQmx » Analog Measurements » Voltage » Cont Acq&Graph Voltag-Ext Clk.vi

I hope, that these examples helped you to clarify the generation and acquisition of data using LabVIEW with DAQmx.

Best regards

Message Edited by MarianMO on 08-17-2009 02:32 PM

[raisch]

Hello marian,

thanks for your answer. I will explain my problem better:

I will in one loop an a RT Systems aquire analog data (with hardware time single point) then compute with a PID controller a number of pulse for the counter/timer output for a step motor. I can't use hardware time single point for the timing output. Examples who can chance Frequency and/or duty circle

i have found, but not a good method for chance the number of pulses in the loop. 

Thanks for your help.

[Marian_O]

Hello Raisch,

generate a number of pulses can be done with the example "Gen Dig Pulse Train-Finite.vi" I mentioned above. These pulses will be generated using the onboard hardware-clock of your NI PXI-6251.

What cycle time of the PID-Loop do you want to achieve?

Best regards from Munich

[raisch]

Hello Marian,

my problem is that I must start the pulse-task then wait generation is finished and final stop the task. (see picture) At this method a have problems with the communication with the RT target (for example: close connetion). The cycle time to aquire is 10Hz and to generate is 1000Hz.

I think, that is not the best way for using in one loop. You have a better idea? 

One Question: can we wrote in german language?

Best Regards

Raisch