Acquire Data with the Analog Input Recorder
This topic shows how to use the Analog Input Recorder app to view and record data from an NI USB-6211 device.
To open the Analog Input Recorder, on the MATLAB® Toolstrip, on the Apps tab, in the Test and Measurement section, click Analog Input Recorder.
Upon opening, the Analog Input Recorder attempts to find all your attached analog and audio input devices.
Opening the Analog Input Recorder deletes all your existing DataAcquisition interfaces in MATLAB.
The DataAcquisition interface created by the Analog Input Recorder is not accessible from the MATLAB command line.
If you plug in a device while the app is open, you must refresh the listing for access to that device. On the Devices tab, click Refresh. Use the same procedure to remove a device from the listing after unplugging it.
Select the device you want to use in the Device List. The app immediately starts a preview of the analog input using default settings.
Modify any scan and channel settings for your specific needs. The following image shows the app displaying three channels of the device. Notice that the Max Rate value has changed with the number of channels; this relationship depends on the device.
Set values for Number of Scans or Duration, and Rate.
Check Continuous if you want to override the duration or number of scans. In this mode, recording continues until you explicitly stop it.
When you are ready to start recording data, click Record.
When recording is complete, either because the specified number of scans is recorded or
you click Stop, the recorded data is assigned to the indicated
MATLAB Workspace variable. By default, the variable starts as
DAQ_1, and its name is incremented with every recording, but you can
specify any valid MATLAB variable name not already in use. The variable is assigned an
M-by-N timetable, where M table rows is the number of scans and N columns is the number of
The following commands show the beginning of the acquired timetable for a multiple channel recording.
Name Size Bytes Class Attributes DAQ_1 1000x3 33315 timetable
View the first four rows of the timetable.
ans = 4×3 timetable Time Dev1_ai0 Dev1_ai1 Dev1_ai2 _________ ________ ________ ________ 0 sec 4.0578 -1.9676 5.1516 0.001 sec 2.8081 -2.5671 4.3738 0.002 sec 1.4604 -3.0992 3.4339 0.003 sec 0.029896 -3.5211 2.3651
The timestamp elements of the table are relative to the first scan. The absolute time of
the first scan is available in the timetable
property. For example,
datetime 19-Nov-2019 15:21:01.239
In the Analog Input Recorder, click Generate Script for the app to open the MATLAB editor and display the equivalent code for recording data. The following code is generated for the finite (non-continuous) 3-channel recording of this example.