CJ2 CPU Unit Software User's Manual - CIP ETI

10 CPU Unit Functions10-5 Memory Management Functions10-5-1 Automatic BackupThe user program and parameters are automatically backed up in backup memory whenever they arewritten to or altered in the CPU Unit.• The following data is backed up automatically: User program, parameters (including the PLC name,PLC Setup, I/O tables, routing tables, and CPU Bus Unit data, such as the data link tables).• The data is backed up automatically whenever the user program or parameters are written in theCPU Unit, including for data transfer operations from the CX-Programmer, online editing, data transfersfrom a Memory Card or EM file memory, etc.• The user program and parameter data written to backup memory is automatically transferred to usermemory in the CPU Unit at startup.10-5 Memory ManagementFunctions1010-5-1 Automatic BackupCPU UnitData transfer fromCX-ProgrammerWrite from file memoryUser memoryUser programOnline editing fromCX-ProgrammerParametersWrite operationAutomatic backupAutomatically restored when PLC isturned ON.Backup memory• The BKUP indicator on the front of the CPU Unit will light while data is being written to backup memory.When transferring the user program from the CX-Programmer or transferring data to the parameterarea from file memory, do not turn OFF the power to the CPU Unit until the backup operation hasbeen completed (i.e., until the BKUP indicator turns OFF). The following table shows the operationsthat will be performed if the power is turned OFF before the backup is completed.CJ2 CPU Unit Software User’s Manual10-39