PLC scan cycle and scan time????

P LC scan cycle and scan time While the PLC is running in running state,scan cycle include four phases,which are repeated  continuously ...

PLC scan cycle and scan time

While the PLC is running in running state,scan cycle include four phases,which are repeated  continuously as individual cycles of operation.

1)INPUT SCAN-Scan the states of the inputs. 

2) PROGRAM EXECUTION-Processes and executes the program logic

3) OUTPUT SCAN-De-energize the outputs.

The time required  to implement a scan cycle is called SCAN TIME