Selected physical channel does not support output type required by virtual channel

[Paul_Knight_Lockheed_Mart]

I am using a USB-6251.  Inside MAX I can set the device mode for Dev1/ ao1 to sinewave generation and have it output a sinewave.  When I use the DAQmx function DAQmxCreateAOFuncGenChan I get the error: Selected physical channel does not support output type required by virtual channel.  Does the DAQmx driver support FuncGen on the USB-6251 or is MAX just outputting a set of voltages?

[John_P1 · Accepted solution]

Hi Paul,

Welcome to the NI Forums!  The DAQmxCreateAOFuncGenChan is only supported on the Elvis II products.  For other devices including the 6251, you need to use the regular DAQmxCreateAOVoltageChan and create your own buffer of data.  I would recommend looking into the following example:

Start >> All Programs >> National Instruments >> NI-DAQ >> Text-based Code >> ANSI C Examples ...

Analog Out >>  Generate Voltage >> Cont Gen Volt Wfm-Int Clk

In MAX the Sinewave output is used as a test signal--in this case MAX is writing a period of sine wave values to the buffer and generating this data.  Again, you may generate a sine wave (or any other function) using the AOVoltageChan, but the AOFunctionGenChan is used only with Elvis II.  You just have to generate the data points for the sine wave that the DAQ device will generate.

-John