Getting Started Acquiring Data with Digilent® Analog Discovery™

This example shows how to acquire analog input voltage data (at a sampling rate of 300kHz). The dynamic range of the incoming signal is -2.5 to 2.5 volts. You will use the session-based interface with the Digilent Analog Discovery hardware.

Create a session with a Digilent device
Add an analog input channel
Set session and channel properties
Acquire a single sample
Acquire timestamped data
Display the results

Create a session with a Digilent device

Discover Digilent devices connected to your system using daq.getDevices and create a session using the listed Digilent device.

s = daq.createSession('digilent')

s = 

Data acquisition session using Digilent Inc. hardware:
   Will run for 1 second (10000 scans) at 10000 scans/second.
   No channels have been added.

Add an analog input channel

Add an analog input channel with device ID AD1 and channel ID 1. Set the measurement type to Voltage.

ch = s.addAnalogInputChannel('AD1', 1, 'Voltage')

ch = 

Data acquisition analog input voltage channel '1' on device 'AD1':

       Coupling: DC
 TerminalConfig: Differential
          Range: -25 to +25 Volts
           Name: ''
             ID: '1'
         Device: [1x1 daq.di.DeviceInfo]
MeasurementType: 'Voltage'

Set session and channel properties

Set the sampling rate to 300kHz and the channel range to -2.5 to 2.5 volts. Set the duration to 0.5 seconds.

s.Rate = 300e3;
s.Channels.Range = [-2.5 2.5];
s.DurationInSeconds = 0.5

s = 

Data acquisition session using Digilent Inc. hardware:
   Will run for 0.5 seconds (150000 scans) at 300000 scans/second.
   Number of channels: 1
      index Type Device Channel MeasurementType       Range        Name
      ----- ---- ------ ------- --------------- ------------------ ----
      1     ai   AD1    1       Voltage (Diff)  -2.5 to +2.5 Volts

Acquire a single sample

Acquire a single scan on-demand, measuring the data and trigger time.

[singleReading, triggerTime] = s.inputSingleScan

singleReading =

   -0.0104


triggerTime =

   7.3532e+05

Acquire timestamped data

Start a clocked foreground acquisition.

[data, timestamps, triggerTime] = s.startForeground;

Display the results

plot(timestamps, data);
xlabel('Time (seconds)'); ylabel('Voltage (Volts)');
title(['Clocked Data Triggered on: ' datestr(triggerTime)])