What are two PLC operations modes ? Describe both modes in brief.

• There are two modes of operation for a PLC processor program mode and run mode. The number of modes may change from product manufacture.

1. Program Mode: The made in which new programs are entered. The program are also used to edit or update existing program and used to upload, download files, document program. When PLC is switched into the program mode, all outputs from the PLC are forced off regardless of their rung Logic status. At the same time. logic Ladder I/O scan sequence is halted.

2. Run Mode: The run mode is used to execute the user program. Input devices are monitored and output devices are energized accordingly. After entering all the instructions to a PLC program, the processes is put in the Run Mode.