A Subsystem is a container Transform that contains other Transforms. This can be used to simplify large Harnesses and to share subsystems between projects, users, and PCs. By dividing a complex harness into subsystems, multiple users can work on it at the same time. The subsystems can be merged into a single Harness by Loading the Subsystems from a file.
To put Transforms into a Container Transform:
1. Double-click on the Container Transform.
MxTransIt opens a new Editor window.
2.Use the Toolbox to create new Transforms in the new window.
3.Export the Ports you wish to be visible on the SubSystem Transform. To avoid confusion, exported port names should be unique.
4.Click the first tab to see the original Editor window. The color of the Transform changes depending on its contents.
1.Select a Transform or group of Transforms by drawing a box with the mouse:
Selecting 3 Transforms
2.Right-click on a selected Transform and select Create Sub-System:
The Sub-system is created as shown below. Ports that are connected outside the Sub-System become ports on the Sub-System.
You can export a Subsystem and the Transforms it contains to an .mxform file. This can be useful for sharing a Subsystem between projects, users, and PCs. The exported file can be edited by another instance of MxTransIt.
1.Choose one of the following:
•Click the Export verb in the Transform's Properties box.
•Right-click on the Subsystem Transform and select Export.
2.Select a name and folder to save the file. Subsystem files have a suffix of mxform.
Referenced subsystems are a good way to divide up a Harness so multiple users can work on it simultaneously. When the parent Harness is opened, its Subsystem Transforms are updated to the current versions stored in the referenced files.
A Test Harness file (.mxform file) can be partitioned into several files (a master Harness file and one or more referenced Harness files). There are several potential benefits to partitioning the Harness, for example:
•To isolate changes to particular areas of the Harness so that the changes can be more easily tracked in a version control system.
•To make parts of the Harness re-usable.
•To partition generic parts of a harness from test-equipment-specific parts of the Harness.
•To allow multiple users to work concurrently on separate parts of the harness without creating the potential merge issues as the individual revisions of the Harness are merged together.
Referenced external Harness files are established in the properties of a Subsystem Transform as described below.
Use this procedure to create a reference to a subsystem (.mxform) file.
1.Click in the External Reference Path property of the Subsystem Transform's Properties box.
2.Browse to the mxform file.
•External subsystems cannot be edited in the parent Harness. To edit the subsystem, open it directly with MxTransIt.
•If you modify a referenced Harness file while an MxSuite project is open there is no notification in MxVDev or MxTransit that the Harness has changed.
•To maintain modularity, avoid changing ports on the Subsystem. If the ports change, the connections in the master Harness must also be changed.
•Nested externally referenced Subsystems are allowed. However, circular references are not. (If A contains B, and B contains C, C cannot contain A.)
Use this procedure to import a subsystem from an .mxform file into a Harness (another .mxform file):
1.Use the Toolbox to create a Subsystem Transform.
2.Click in the External Reference Path property of the Subsystem Transform's Properties box.
3.Browse to the mxform file.
At this point, it is a referenced subsystem.
4.Delete the path from the External Reference Path property to break the link and import the subsystem into the parent .mxform file.
5.Click to save the Harness.
Unlike a referenced subsystem, when a subsystem has been imported, changes to the subsystem file are not incorporated into the parent Harness.
If you change the contents of the Subsystem (for example, by deleting a port on a contained Transform), you may need to restart MxTransIt to update the ports on the Subsystem Transform.