Cheapest way to generate a PWM for a relay with LabView2010 and a Laptop

[Kambra]

Hello there,

like mentioned in the title I'm searching for the cheapest way to generate a PWM signal for a relay. I want to use a Laptop and LabView2010 for it. I read through several  topics but after time it just got more confusing. For example the NI USB-6008 OEM seems to be a cheap solutiion, however I'm not sure if I can use for the PWM signal generation as this thread says it's not possible:

http://forums.ni.com/t5/Multifunction-DAQ/Using-PWM-on-NI-6008/m-p/231860/highlight/true#M13339

But then again this thread right over here makes it seem like it's do-able:

http://forums.ni.com/t5/Digital-I-O/Generating-a-PWM-using-USB-6008/m-p/421654/highlight/true#M5527

So again in short form.

What I need:

- the cheapest way to generate a PWM signal to control a relay

What I have until now:

- LabView2010

- Laptop

If possible it would be great to have two channels for two seperate signals, but this is of lower importance right now.

[Phox3 · Accepted solution]

Hey Kambra,

   The first thread you mention is correct, you cannot do PWM output in any kind of deterministic fashion with a 6008. The 6008 is strictly software timed, meaning that each digital write that is done to the device has to go through the OS and down to the device. And there will be a lot of jitter from the OS involved. The second article you mention says the same thing. They noted that they were able to reduce the jitter some, but still could not remove it entirely. In the second thread, they mention using a USB M-series device to do deterministic (hardware timed) PWM output. 

  The trade-offs really come down to your application and it's requirements. If your application for controlling the relay doesn't require any determinism, then you can use the 6008. If you need precise control over the relay, try the USB M-series.

[Kambra]

Thanks for the help. Turned out we have a NI USB-6211 here so I'm going to use that.