System configuration memory, user data memory, and user program memory can be backed up in any of three different methods: With an optional battery capacitor (110XCP99000), In a kept area in the PLC’s Flash, with an optional lithium battery (110XCP98000)
Optional Backup Techniques
If an assembly of lithium battery or assembly of battery capacitor is used, it repeatedly backs up the present memory values in the power loss event. When power is reinstated, the PLC goes back up prepared with the program and configuration values that were current at the time power was gone. The battery of lithium safely backs up memory data for a year. The battery of capacitor can back up a characteristic user logic program for up to 72 hours.
Using Flash for Backup
The Flash memory portion in all PLCs of Modicon Micro is kept for saving the user logic, system configuration, and user data memory, excepting the 61204. Due to limitations of the capabilities of Flash storage in the 61204, a battery is connected to the hardware. This feature permits you to back up the user logic and configuration even if you do not apply a battery or battery capacitor. You have to issue a save to Flash control from the software of panel to save the memory in Flash. The memory values at the time you send the save are the only memory values saved in Flash. The operation of save to Flash is permitted only in a PLC after it has been constructed and while it is closed. If memory is reinstated to the PLC from Flash backup after a power defeat, the values that were present at the time of your last store operation will be reinstated.
PLC Power-up Procedures
It initial checks the memory of system configuration to observe if an official configuration exists when the PLC accepts power. If an official configuration has been stored through the optional battery backup, these values will be current in the user of data memory. The PLC will construct itself with these values and be ready to work. If the PLC does not notice a suitable configuration in the user of data memory, it will verify the backup of Flash. If a suitable configuration has been stored in Flash, the PLC will construct itself with these values and be ready to work.
If the PLC can’t discover a suitable configuration in Flash or in memory, it will power up in a condition of unconfigured. You need to link a panel of programming to the PLC and construct it before it can solve logic or before can be programmed.