Omron CP1E - INTRODUCTION Introduction Manual page 117

I/O Refreshing
I/O refreshing refers to cyclic data transfers between a preset area of the memory
and an external source. It involves the following refreshing processes.
CPU unit's built-in I/O
CP-series expansion I/O unit, expansion unit
I/O refreshing is performed without interruption within a single cycle. Furthermore,
I/O refreshing is always performed after program execution.
I/O refreshing can be performed for CP1L/CP1E's built-in normal I/O and CP-
series expansion (I/O) units at one of the following 3 timings:
• Cyclic refreshing
• Execution by instructions with immediate refresh variation
• Execution by an IORF instruction
Cyclic Refreshing
I/O refreshing is performed after all instructions in the executable tasks have been
executed.
This is the standard method for I/O refreshing.
Cycle
Target Unit Type
END
END
END
I/O refresh
A-3 Inner Workings of CP1L/CP1E
Max. Data Exchange
Input: 3 CH I/O area
Output: 3 CH
Fixed; dependent on unit I/O area
Task
Task
Task
Actual
I/O data
SYSMAC CP1L/CP1E Introduction Manual
Data Exchange Area
115
A