Measure Voltage Between Ain0 And Ain1 In Differential Mode With The Labjack U6 And The Daqfactory Interface

[davis]

Hello,

How can I measure a voltage between AIN0 and AIN1 in differential mode with the LabJack U6 and the DAQFactory software interface please ?

Thanks

[AzeoTech]

Differential between 0 and 1? Set the Channel # to 0, then in the Quick Note / Special / OPC column, put 1 for the negative channel. See section 9.1.2 in the DAQFactory Labjack Application guide.

[LabJackSupport]

And also Section 3.2 of the DF-LJ App Guide:

http://labjack.com/support/ud/df-lj-app-guide/3.2

http://labjack.com/support/ud/df-lj-app-guide/9.1

Also see the following general app note about differential inputs:

http://labjack.com/support/app-notes/differential-analog-inputs

[BeeHay]

There are a few function calls you can do from a auto-start sequence to set-up your U6...

Do you know the ranges of your voltage input??

You can set AIN0 to a +-1.0V range as so -

// set AIN0 range to +/-1.0 here!!
ePut(ID, LJ_ioPUT_AIN_RANGE, 0, LJ_rgBIP1V, 0)
ErrorHandler(ID)
[/CODE]

Set AIN2 to a +-10.0V range as so -

[CODE]
// set AIN2 range to +/-10.0V here!!
ePut(ID, LJ_ioPUT_AIN_RANGE, 2, LJ_rgBIPP10V, 0)
ErrorHandler(ID)
[/CODE]

Set AIN4 to +-0.01V range as so -

[CODE]
// set AIN4 range to +/-0.01V here!!
ePut(ID, LJ_ioPUT_AIN_RANGE, 4, LJ_rgBIPP01V, 0)
ErrorHandler(ID)
[/CODE]

And as AzeoTech said, in your Quick Note/Special column, you need the Odd number of the input channel set there...(AIN0 has a "Quick Note/Special" of 1, AIN2 has a "Quick Note/Special" of 3, ect ect)..

Do you have a U6-Pro?

I like to set my resolution to the max with this function call -

[CODE]
// set device resolution to index 12
ePut(ID, LJ_ioPUT_CONFIG, LJ_chAIN_RESOLUTION, 12, 0)
ErrorHandler(ID)
[/CODE]

Be sure you have this at the beginning of the Start-up sequence (along with the LJ drivers installed) -

[CODE]
using("device.labjack.")
include("c:\program files (x86)\labjack\drivers\labjackud.h") //64bit Windows
global ID = 1
[/CODE]

And then in your channels menu, be sure to set your D# to 1...

Hope this helps!