How To Use - Gen Dig Pulse Train-Continuous.vi

[arron]

Using Gen Dig Pulse Train-Continuous.vi it outputs the correct signal as specified but it will not change when I change the value in a control.
For example if I set up initially with Frequency=500Hz, duty cycle=0.5, Idle=LOW, on Dev1/ctr0 then hit run it outputs the signal. However if I change any of these parameters, f=100Hz, the output does not update. I have to stop the VI then run it again to update the output.

SO, how do I get the output to update whenever I change the value of a control? Is there some sort of Restart command?
If I use an event which occurs on a change of value of frequency for instance what do I need to do in that event for it to update?
......Please help!

- Thanks,Aaron
LabView 7.1
Win2000, P4

[AnalogKid2DigitalMan]

Looking at the code for that example, there is no data flow to update pulse specs once the program is started.

Is this what you are looking for?

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=DE27921DB53A4D8DE034080020E74861 

[arron]

OK, but it still does not update the output when I write/change the frequency. What am I doing wrong?
Attached are my 3 simple VIs:
6601Counter_Write_Read.vi - main VI which sets the frequency(PFI_32) and then read/displays it from another source(PFI_38)
RPM_3.vi - Reads the frequency from CNTR0
GenDigPulseTrain-ChangingSpecs.vi - Generates the pulse train

Thanks for your help, Aaron

[Ryan_V[DE]]

Arron,

The reason that you are not able to update you counter output is that you have placed the "GenDigPulseTrain-ChangingSpecs" VI as a sub VI within "6601Counter_Write_Read." Values will only be passed to it when it is initially run. In fact, the way your code is written, the while loop within "6601Counter_Write_Read" will only execute its first iteration. Try opening up the block diagrams of all your VIs and enabling "Highlight Execution" (the light bulb) to see what I mean. This should give you a little more insight into dataflow programming.

In order to remedy this, you would need to run "GenDigPulseTrain-ChangingSpecs" and "RPM_3" simultaneously (not using "6601Counter_Write_Read") and manipulate the controls on their respective front panels.

Hope this helps,
Ryan V.
National Instruments