I/O Refresh Timing - Omron SYSMAC CP Series User Manual

4 Understanding Programming
4-4-7

I/O Refresh Timing

The following methods are used to refresh external I/O.
• Cyclic refreshing
• Immediate refreshing (instructions with the ! variation and IORF)
Cyclic Refreshing
I/O is all refreshed after ladder programs are executed.
Start
LD1.01
OUT2.09
END
I/O refresh
Execute an instruction with the immediate refresh variation or an IORF instruction to perform I/O
refreshing while ladder programming is being executed.
Immediate Refresh
The method of specifying immediate refreshing depends on whether the object to be refreshed is built-
in I/O or an Expansion Unit.
• To specify immediate refreshing for the CPU Unit's built-in I/O, specify the immediate refresh variation
(!) of the instruction.
• To specify immediate refreshing for Expansion I/O or an Expansion Unit, use the IORF instruction.
Instructions with Refresh Variation (!)
Add an exclamation mark (!) in front of the instruction to specify immediate refreshing.
I/O will be refreshed as shown below when an instruction is executing if a real I/O bit in the CPU
Unit's built-in I/O is specified as an operand.
• Bit Operands: I/O refreshing for the bit will be performed.
• Word Operands: I/O refreshing for the 16 specified bits will be performed.
• Input or Source Operands: Inputs are refreshed immediately before the instruction is executed.
• Output or Destination Operands: Outputs are refreshed immediately after the instruction is executed.
IORF(097) Instruction
An I/O refresh (IORF) instruction is supported as a special instruction to refresh actual I/O data in
the specified word range. By using this instruction, it is possible to refresh all data or data in a spec-
ified range of actual I/O in CP-series Expansion I/O and Expansion Unit during the cycle.
Precautions for Correct Use Precautions for Correct Use
It is not possible to use the immediate refresh variation (!) for the actual I/O of Expansion I/O or
an Expansion Unit. Use the IORF instruction.
4-22
15
CIO 0001
15
CIO 0002
All actual I/O data
Cyclic refreshing
(batch)
0
16-bit increments
0
CP2E CPU Unit Software User's Manual(W614)