Omron CP1L CPU - Page 109

A
A-3 Inner Workings of CP1L
108 SYSMAC CP1L Getting Started Guide
Appendix
 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.
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’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
zCyclic 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.
Target Unit Type Max. Data Exchange Data Exchange Area
CPU unit’s built-in I/O Input: 2 CH
Output: 2 CH
I/O area
CP-series expansion I/O unit, expansion unit Fixed; dependent on unit I/O area
I/O refresh
END
Actual
I/O data
END
END
Task
Task
Task
Cycle
W07E-EN-02+CP1L+GettingStartedGuide.book Seite 108 Montag, 15. September 2008 11:15 11