Tips & Tricks
What are some Best Practices for managing Unity MODICON PAC Firmware

Users considering an upgrade of controller firmware must be familiar with all of the impacts to their systems and all of the procedures documented in Unity Pro and related Schneider Electric Manuals.

First, it is not necessary to upgrade firmware simply because there is a new version of Unity Pro.
Unity Pro is back-ward compatible with firmware; e.g. Unity Pro V7.0 can be used to maintain a project created in V5.0.
Unity Pro does this by including (in the install) the EF/EFB libraries for all released versions of Unity Pro, and when the V5.0 project is opened, Unity Pro uses the V5.0 library.

Also, a Unity Pro Project can be upgraded to the latest EF/EFB Library without changing the firmware. This subject is addressed in What are some Best Practices for managing Unity Pro Projects.

Before proceeding with a Firmware Upgrade, consider this...

1. Does the firmware require upgrading?
    a. Is Schneider Electric recommending or requiring the upgrade?
    b. Is there new functionality that is required and only available by firmware upgrade?

If the answer to all of these questions is No, then "if it ain't broke, don't fix it".

Else, here are highly recommended steps to follow:

1. If the system contains:
    a. Cummulative data (e.g.: Flow Totalizations, Motor Runtimes, etc)
    b. Dynamically or User Interactively set data (by Animation Tables, HMIs, SCADA, etc.) like Setpoints, Tuning Parameters, etc.
    c. Data stored in Variables located in State RAM (%MW or formerly 4x), Unlocated Variables or DFBs which it is desired to be maintained

    Then use the Unity Pro feature 'Save Data from PLC to File' immediately before stopping the controller to perform the firmware upgrade.
    This Unity Pro feature is in the PLC menu. Use the default file type (filename.dtx).    Show me this feature.

2. Perform the firmware upgrade according to the Schneider Electric procedures.
    This will clear both the application code and data from the controller.

3. Change the firmware version of the controller in the Unity Pro project to the firmware version loaded.
    This is done in the Configuration Editor.    Show me this feature.
    Build the project.

4. Download the Unity Pro project to the controller.
    a. If step #1 was performed, then DO NOT START THE CONTROLLER.
    b. Use the Unity Pro feature 'Restore Data from File to PLC' and transfer the file (filename.dtx) saved in step #1.
        This Unity Pro feature is in the PLC menu.    Show me this feature.

5. Follow all Schneider Electric procedures, insuring that the system is safe, and then start the controller.