ni-9205 software commands

[victor31]

I have put together a customized C# routine that controls multiple modules in an NI-9172 CDAQ.  One of those modules is an NI-9205 A/D.  I'm not sure I have it configured correctly for the differential measurements I am trying to make.  Is there a software users manual for this device or for the CDAQ that shows how to configure the module for various analog input arrangements?

[Ryan_T]

Hi victor31,

In order to take differential measurements with the 9205 you will want to refer to page 12 of this document. In terms of DAQ programming, we do not have an individual software manual for each module, but we do have many text based examples that are installed when you install DAQmx.  These can be found by navigating to Start » All Programs » National Instruments » NI-DAQ » Text-Based Code Support. 

[victor31]

Thanks for the information.  I looked at some sample code for both a single analog voltage read and continuous voltage read.  I also went into MAX and created a task to read voltage off the terminals.  In MAX the wizard allows me to select differential or single ended input.  However, I have no access to any code it generated for the task.  The C code commands to configure the input as diff or single ended are what I need.  I very well may be intending to read differential voltage with the 9205, but I may have it configured for single ended measurement.  In this case I may be able to read a voltage value into the module, but it may have noise associated with it.  Where can I find the specific command list that dictates the configuration?  In the "AcqOneVoltageSample" example I sifted through the code and found this statement: 

'Create a virtual channel

myTask.AIChannels.CreateVoltageChannel(physicalChannelComboBox.Text, "", _

CType(-1, AITerminalConfiguration), Convert.ToDouble(minimumValueNumeric.Value), _

Convert.ToDouble(maximumValueNumeric.Value), AIVoltageUnits.Volts)

I assume this dictates the termination of the input, but it gives no indication of differential or single ended.  Does the "-1" refer to that?  If so, where is this documented?  I don't know if I need to read AI0 and AI8 then take the difference, or if the differential configuration will do this for me.  I've searched the help but cannot find anything that provides these details.

[John_P1]

Hi Victor,

The documentation you're looking for is in the NI-DAQmx .NET Framework Help (see here).


Here's a screenshot showing the page of interest:

Passing -1 and casting it to an AITerminalConfiguration will give you the default value, which I believe for the 9205 should default to Differential (you may want to verify this).  The members of the AITerminalConfiguration Enumeration are as follows:

Best Regards,