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4-3-7
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.
IORF instruction can also refresh actual I/O data in an NA-type CPU Unit at CIO 90, CIO 91 and CIO 190.
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.
CP1E CPU Unit Software User's Manual(W480)
15
CIO 0001
15
CIO 0002
All actual I/O data
Cyclic refreshing
(batch)
4 Understanding Programming
0
16-bit increments
0
4
4-15
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