Using an External Data Source

The External Data Source property of a DataBlock is a useful way of storing test data in an external file rather than in an MxVDev TestCase. It is also an easy way to import data for a single signal. Using an external data source has several advantages:

It is a more efficient way of storing data. An external CSV file is smaller than an equivalent XML TestCase (.mxc) file .

Multiple TestCases can use a single data file.

It is useful way to reduce memory usage when working large data sets such as image data.

External data may come from many sources.  For example, you might:

Have test data created from a simulation run in Simulink

Capture test data from test stand instrumentation, such as a digital scope, or CANoe

Create your own test data using an Excel spreadsheet

Create a data file from internal MxVDev signal data

Have data exported from a TestCase

The External Data Source property allows you to use an external data file to specify the commanded values or expected results for a particular Signal.


When you have a DataBlock with an external data source, if you re-select the Data Location option as Internal, the data that was read from the file remains in the TestCase as a sequence of Transitions.  This is one way to import data from a file.

When loading external data, only the transitions in the selected DataBlock's range are loaded.

The times in the external data file should be relative to the DataBlock's start time.

hmtoggle_plus1Selecting the External Data Source
hmtoggle_plus1Creating an External Data File from an MxVDev Signal


Related Topics:

DataBlock Overview

Importing Test Data

Exporting Test Data