PXI-6733 vs current setting

[michalkubik]

Maybe this question is bit primitive, but ...

Is it possible to set Current output on PXI-6733 High-Speed Voltage Output?

I have tryed and i think answear is no, because i've got this message

DAQmx Error Selected physical channel does not support the output type required by the virtual channel you are creating.

Create a channel of an output type that is supported by the physical channel, or select a physical channel that supports the output type.
Property: DAQmx_AO_OutputType
You Have Requested: DAQmx_Val_Current
You Can Select: DAQmx_Val_Voltage

I've tryed it this way:

 DAQmxErrChk (DAQmxCreateTask("",&taskHandle));
 DAQmxErrChk (DAQmxCreateAOCurrentChan(taskHandle,"dev4/ao0","",0.0,0.2,DAQmx_Val_Amps,""));

 DAQmxErrChk (DAQmxStartTask(taskHandle));

 DAQmxErrChk (DAQmxWriteAnalogF64(taskHandle,1,1,10.0,DAQmx_Val_GroupByChannel,data,NULL,NULL));

and error gave me command DAQmxCreateAOCurrentChan.

On the other hand if i try to set Voltage output, everything works just fine.

Thanks Michal

[Jarrod_B.]

Hello Michael,

Your assumption is correct, the PXI-6733 does not support current output.  If you want a device that supports current output, you have a few options. 

First of all, determine what your timing requirements are.  From the code you posted, it looks like you were performing static analog output (hardware-timed would call the DAQmxCfgSampClkTiming function).  If this is the case, the PXI-6704 has 16 static current output channels (0-20 mA).

If you really do need hardware-timed current output, there are still a few options.  The PXI-6238 and PXI-6239 each have two current output channels (0-20 mA) that can be updated up to 500 kS/s.  The only difference between these two boards is that the 6238 has sourcing digital I/O lines while the 6239 has sinking digital I/O.  The other option would be to use an NI 9265 module in a CompactDAQ chassis.  This would give you four current output channels at 0-20 mA that can be updated at 100 kS/s.  The nice thing about this approach would be the USB connectivity. 

I hope this information helps as you evaluate your options. 

Best regards,