Topic: DMD0270

Clear PLC Memory

The Clear PLC Memory utility provides the ability to clear the user-created content from a Do-more controller. Using the Clear PLC Memory utility will require that the online connection was established with a user account with sufficient privileges. The different sections require different privileges. These privileges are assigned to user accounts through the System Security utility.

 

 

The Select PLC Memory to Clear group lists the various sections of the user-created content that can be removed from the controller.

 

  • All - the default selection - this selects all of the following sections of the controller to clear.

 

  • Program - Clears the user program from the controller, this includes the contents of all System Tasks, and any user-created Programs and Tasks. Clearing the Program section requires the Write Program (WP) privilege.

 

  • System Configuration - Clears the entire system Configuration which includes the CPU Configuration, the I/O configuration, the Module configuration, the device configuration, any changes to the I/O Mappings, and any changes to the Memory Configuration. Clearing the System Configuration section requires the Write Program (WP) privilege.

     

    Warning: Selecting the System Configuration section will also select the Program section. The Program is tightly bound to the contents of the System Configuration. Clearing the System Configuration can remove contents that the Program depends upon, which would leave the user with an invalid Program.

     

  • Documentation - Removes all of the user-generated documentation, which includes Element documentation (nicknames, wiring info, and descriptions), and the ladder rung comments. Clearing the Documentation section requires the Write Program (WP) privilege.

     

    Warning: Selecting the Documentation section will also select the Program section.
     

  • System RAM - Clears the retentive memory sections of RAM in the controllers, which includes the areas where the System Log, the User Log, and the Force Table are stored. Clearing the System RAM section requires the Write Data (WD) privilege and the System Settings (SS) privilege.

     

  • Image Register - Clears all of the image register locations on the controller which includes all of the memory locations that are accessible to the user program, for example, WX memory, WY memory, V memory, D memory, etc. Clearing the Image Register section requires the Write Data (WD) privilege.

     

  • System Settings - Clears the controllers System Settings which includes the IP configuration (IP Address, Subnet Mask, Gateway Address), the Node Name, and the Description. Clearing the System Settings section requires the System Settings (SS) privilege.

     

    Warning: Selecting the System Settings section will cause the online session to fail because the IP configuration of the Do-more controller has been cleared.

     

  • Password Configuration - Removes all of the user-created accounts from the password configuration. Clearing the Password Configuration section requires the Set Password (PW) privilege.

     

The Select Project to View group contains optional actions to take after the clear operations are performed after processing a Clear PLC Memory operation. These actions are needed because the Clear PLC Memory only affects the specified sections in the controller, it does NOT affect any of the data in the currently open project.

 

  • Read from PLC after completion - enabling this option will cause Do-more Designer to reread the all of the above sections from the controller once the specified Clear operations have completed. Any unsaved changes to the Project will be discarded.

 
Initialize Cleared PLC

After the PLC memory has been successfully cleared, Do-more Designer will run the Initialized Cleared PLC wizard that steps the user through the process of initializing the most important sections of the PLC's memory.

 

 

The first step of the wizard will open the Set PLC Clock dialog where the programmer can set the following:

 

  • the current time
     

  • the Time Zone
     

  • the Daylight Saving Time mode

 

A default system configuration is created after the PLC 's memory has been successfully cleared. The second step of the wizard will invoke the System Configuration utility where the default configuration can be viewed, and changed as required.

 

 

This includes setup of the following:

 

  • the CPU's on-board serial and Ethernet port
     

  • the I/O subsystem
     

  • any I/O modules that require additional configuration
     

  • any additional devices that access the system's ports or I/O modules
     

  • the I/O mapping

 

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