Acquire Sound Pressure Data
This example shows how to acquire sound data from an NI 9234. The
device is in an NI cDAQ-9178 chassis, in slot 3 with ID
cDAQ1Mod3
.
Create a DataAcquisition object, and add an analog input channel with
Microphone
measurement type:
d = daq('ni'); ch = addAnalogInputChannel(d,"cDAQ1Mod3",0,"Microphone");
Set the channel sensitivity to 0.037 v/pa.
ch.Sensitivity = 0.037
ch = Data acquisition analog input microphone channel 'ai0' on device 'cDAQ1Mod3': Sensitivity: 0.037 MaxSoundPressureLevel: 136 ExcitationCurrent: 0.002 ExcitationSource: Internal Coupling: AC TerminalConfig: PseudoDifferential Range: -135 to +135 Pascals Name: '' ID: 'ai0' Device: [1x1 daq.ni.CompactDAQModule] MeasurementType: 'Microphone' ADCTimingMode: ''
Change the maximum sound pressure level to 100 dB.
ch.MaxSoundPressureLevel = 100
ch = Data acquisition analog input microphone channel 'ai0' on device 'cDAQ1Mod3': Sensitivity: 0.037 MaxSoundPressureLevel: 100 ExcitationCurrent: 0.002 ExcitationSource: Internal Coupling: AC TerminalConfig: PseudoDifferential Range: -135 to +135 Pascals Name: '' ID: 'ai0' Device: [1x1 daq.ni.CompactDAQModule] MeasurementType: 'Microphone' ADCTimingMode: ''
Acquire 4 seconds of data and save it in a variable.
[data,time] = read(d,seconds(4),"OutputFormat","Matrix");
Plot the data.
plot(time,data)