380
I/O Area Section 9-3
IORF(097) Refreshing When IORF(097) (I/O REFRESH) is executed, the input bits in the specified
range of words are refreshed. This I/O refreshing is performed in addition to
the normal I/O refreshing performed once each cycle.
The following IORF(097) instruction refreshes the status of all I/O points in I/O
Area words CIO 0000 to CIO 0003. The status of input points is read from the
Input Units and the status of output bits is written to the Output Units.
In the following example, the status of input points allocated to CIO 0000 and
CIO 0001 are read from the Input Unit. (CIO 0002 and CIO 0003 are allocated
to Output Units.)
Limitations on Input bits There is no limit on the number of times that input bits can be used as nor-
mally open and normally closed conditions in the program and the addresses
can be programmed in any order.
An input bit cannot be used as an operand in an Output instruction.
000101
!LD 000101
CIO 000101
CPU UnitInput Unit
Read
just
before
instru-
ction
execu-
tion.
Switch 7
Switch 1
Switch 0
Ladder symbol Mnemonic
Input Unit CPU Unit
Read
when
IORF
(097)
is
execu-
ted.
Switch 0
Switch 1
Switch 15
Switch 16
Switch 17
Switch 31
00001
000100
Not allowed if CIO 000100 is an input bit.
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