ExcitationSource

External source of excitation

Description

When working with the session-based interface, the ExcitationSource property indicates the source of ExcitationVoltage for bridge measurements or ExcitationCurrent for IEPE sensors and RTDs. Excitation source can be:

• Internal

• External

• None

• Unknown

By default, ExcitationSource is set to Unknown.

Example

Change Excitation Source

Change the excitation source of a microphone channel.

Create a session and add an analog input microphone channel.

s = daq.createSession('ni');
ch = addAnalogInputChannel(s,'cDAQ1Mod3',0,'Microphone')

ch = 

Data acquisition analog input microphone channel 'ai0' on device 'cDAQ1Mod3':

          Sensitivity: 'Unknown'
MaxSoundPressureLevel: 'Unknown'
    ExcitationCurrent: 0.004
     ExcitationSource: Unknown
             Coupling: AC
       TerminalConfig: PseudoDifferential
                Range: -5.0 to +5.0 Volts
                 Name: ''
                   ID: 'ai0'
               Device: [1x1 daq.ni.CompactDAQModule]
      MeasurementType: 'Microphone'
        ADCTimingMode: ''

Change the excitation source value to 'Internal'.

ch.ExcitationSource = 'Internal'

ch = 

Data acquisition analog input microphone channel 'ai0' on device 'cDAQ1Mod3':

          Sensitivity: 'Unknown'
MaxSoundPressureLevel: 'Unknown'
    ExcitationCurrent: 0.004
     ExcitationSource: Internal
             Coupling: AC
       TerminalConfig: PseudoDifferential
                Range: -5.0 to +5.0 Volts
                 Name: ''
                   ID: 'ai0'
               Device: [1x1 daq.ni.CompactDAQModule]
      MeasurementType: 'Microphone'
        ADCTimingMode: ''