5 Understanding Programming
5-82
CJ2 CPU Unit Software User’s Manual
With immediate refreshing, refreshing is performed whenever an instruction is executed in the program.
z Types of Immediate Refresh
There are two ways to perform immediate refreshing: using an instruction and specify the immediate
refresh variation (!) or using a special instruction for immediate refreshing.
Instructions with Refresh Variation (!)
Refreshing can be performed when the instruction is executed (i.e., during the cycle) by using the
immediate refresh variation (!) of the instruction.
Special Instructions for Immediate Refresh
The following three instructions can be used depending on the Unit for which memory is to be
refreshed.
IORF(097) instruction: Basic I/O Units and Special I/O Units (word allocated in CIO Area only)
FIORF(225) instruction: Special I/O Units
DLNK(226) instruction: CPU Bus Units
The following table shows which Units can be refreshed with which instructions.
*1 EtherNet/IP Units, Controller Link Units, data links for SYSMAC LINK Units and DeviceNet remote I/O commu-
nications.
*2 Words allocated in the CIO Area to Special I/O Units can be refreshed by using either the IORF(097) instruc-
tion or the FIORF(225) instruction. Instruction execution time is shorter with the FIORF(225) instruction than
with the IORF(097) instruction. It is also easier to use because all that is required is specifying the unit number
of the Special I/O Unit in the operand.
*3 Immediate refreshing is possible only for inputs set as normal inputs or quick-response inputs and for outputs
set as normal outputs.
Precautions for Correct UsePrecautions for Correct Use
The execution times for immediate-refreshing variations are longer than the regular variations of
instructions, so be careful because the cycle time will be longer.
Immediate Refresh
Unit
Instruction
with immedi-
ate refresh
variation (!)
IORF(097)
instruction
FIORF(225)
instruction
DLNK(226)
instruction
Basic I/O Units Yes Yes No No
Words allocated in CIO Area
Special I/O Units No
Ye s
*2
Ye s
*2
No
Words allocated in CIO Area
Words allocated in DM Area No
CPU Bus Units No No No YES
Words allocated in CIO Area
Words allocated in DM Area
Unit-specific memory
*1
Pulse I/O Modules for CJ2M CPU Units
Ye s
*3
No No No
Words allocated in CIO Area
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