Speedy Badger
2007-11-13 16:10:13 UTC
Hello MogeMbo,
Fortunately you can still generate pulse width modulated signals using the PCI-6518. The only caveat to keep in mind is that this board has no counters and the DIO lines are entirely static. This means that your application will be entirely software timed and at the mercy of the system you are running it on. That being said, I have included a simple example which illustrated two methods of generating pulse width modulated signals.
The first method uses the counter on a while loop to determine the length of the positive pulse.
The second method allows you to switch between two pre-made pulse lengths.
In either case, the timing is controlled by a software timing structure (delay) within the main while loop. This can be controlled on the front panel to increase or decrease the ?frequency? of the signal. As mentioned above however the accuracy of this timing is dependent on the system.
Below are some great resources which will help you understand the DAQmx driver and how to program various applications using our DAQ hardware.
<a href="http://zone.ni.com/devzone/cda/tut/p/id/5434" target="_blank">Getting Started with NI-DAQmx </a>
<a href="http://zone.ni.com/devzone/cda/tut/p/id/2835" target="_blank">Learn 10 Functions in NI-DAQmx and Handle 80 Percent of Your Data Acquisition Applications </a>
Let me know if you have any questions about this example.
Regards,
PWM on Static DIO (LabVIEW 8.0)1.vi:
http://forums.ni.com/attachments/ni/70/7764/1/PWM on Static DIO (LabVIEW 8.0)1.vi
Fortunately you can still generate pulse width modulated signals using the PCI-6518. The only caveat to keep in mind is that this board has no counters and the DIO lines are entirely static. This means that your application will be entirely software timed and at the mercy of the system you are running it on. That being said, I have included a simple example which illustrated two methods of generating pulse width modulated signals.
The first method uses the counter on a while loop to determine the length of the positive pulse.
The second method allows you to switch between two pre-made pulse lengths.
In either case, the timing is controlled by a software timing structure (delay) within the main while loop. This can be controlled on the front panel to increase or decrease the ?frequency? of the signal. As mentioned above however the accuracy of this timing is dependent on the system.
Below are some great resources which will help you understand the DAQmx driver and how to program various applications using our DAQ hardware.
<a href="http://zone.ni.com/devzone/cda/tut/p/id/5434" target="_blank">Getting Started with NI-DAQmx </a>
<a href="http://zone.ni.com/devzone/cda/tut/p/id/2835" target="_blank">Learn 10 Functions in NI-DAQmx and Handle 80 Percent of Your Data Acquisition Applications </a>
Let me know if you have any questions about this example.
Regards,
PWM on Static DIO (LabVIEW 8.0)1.vi:
http://forums.ni.com/attachments/ni/70/7764/1/PWM on Static DIO (LabVIEW 8.0)1.vi