Omron CJ2 CPU UNIT SOFTWARE User Manual page 174

5 Understanding Programming
Immediate Refresh
With immediate refreshing, refreshing is performed whenever an instruction is executed in the program.
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.
Basic I/O Units
Words allocated in CIO Area
Special I/O Units
Words allocated in CIO Area
Words allocated in DM Area
CPU Bus Units
Words allocated in CIO Area
Words allocated in DM Area
Unit-specific memory
Pulse I/O Modules for CJ2M CPU Units
Words allocated in CIO Area
*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 Use Precautions 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.
5-82
Instruction
with immedi-
Unit
ate refresh
variation (!)
Yes
No
No
*1
*3
Yes
IORF(097) FIORF(225)
instruction instruction
Yes No
*2 *2
Yes Yes
No
No No
No No
CJ2 CPU Unit Software User's Manual
DLNK(226)
instruction
No
No
YES
No