Operating systems and Application Programs in PLC

A PLC retains its operating system, user programs, and some data in retentive (nonvolatile) memory

– While the PLC is off or is even disconnected from the power supply (given a battery backup)

A PLC can then resume running a user program as soon as power is restored

– The PLC may be programmed to require some operator action before resuming user program execution (for safety purposes)

1 Like