How to properly use AOChannels.CreateFunctionGenerationChannel with a 6025E daq

[Argneka]

Hi,

What is the best way to use AOChannels.CreateFunctionGenerationChannel to generate a square wave pattern.  Here is what I am attempting to do:

myTask =

new Task();

myTask.AOChannels.CreateFunctionGenerationChannel(

"Dev1/ao0", "aoChannel", AOFunctionGenerationType.Square, 45.0, 5.0);

myTask.AOChannels[0].FunctionGenerationSquareDutyCycle = 50.0;

writer =

new AnalogSingleChannelWriter(myTask.Stream);

 An exception with Status Code: -200432 : Create a Channel of an Output type that is supported by the physical channel, or select a physical channel that supports the output type.

Thanks,

Argneka

[Canisius]

Hi Argneka,

The only device that supports CreateFunctionGenerationChannel is NI Elvis 2 and the physical channel has to be "fgen". So if Dev1 is not an NI Elvis 2 device then you will get the exception. If Dev1 is an NI Elvis 2 device, then please change ao0 to fgen and the method should work.

Please let us know if you have anymore questions.

Regards,

Canisius

[Argneka]

Hi,

Ok,  then is there an easy way to generate a square wave on one of the 2 Analog output ports on the 6025E?  I need to be able to set freq and duty cycle.

Thanks,

Alan

[J_Thomas]

Hi Argneka,

There are two possible options that may work for you.

1. Use the analog output channels.  This example may help you get started.

Continuous Analog Output on Multiple Channels with C#

2. Use the counters on your board to generate a pulse train.

DAQmx - Retriggerable Pulse Train Generation - LabVIEW - CVI - ANSI C - VB.NET - C#.NET

You can also look at the examples that should have been installed when you installed the NI-DAQmx driver.  They are usually found at:

C:\Documents and Settings\USERNAME\Documents\National Instruments\NI-DAQ\Examples

Hope this helps.

[Argneka]

Thanks,

This example is excally what I am looking for.  I am already using the co outputs and these work fine. 

Thanks for in great insight,

Alan