771
Basic I/O Unit Instructions Section 3-22
Flags
Precautions An error will occur if words in both the I/O Bit Area (CIO 0 to CIO 999) and the
Special I/O Unit Bit Area (CIO 2000 to CIO 2959) are specified for the same
instruction.
The I/O refreshing initiated by IORF(097) will be stopped midway if an I/O bus
error occurs during I/O refreshing.
When IORF(097) is used in an interrupt task, be sure to disable Special I/O
Unit cyclic refreshing in the PLC Setup. If cyclic refreshing for Special I/O
Units is enabled and I/O refreshing is executed again by IORF(097), a non-
fatal Duplicate Refreshing Error will occur and the Interrupt Task Error Flag
(A402.13) will be turned ON.
Examples Refreshing Words in the I/O Bit Area
When CIO 0.00 turns ON in the following example, CIO 2 to CIO 4 (36 inputs)
are refreshed (1) and then after the required processing is performed (2),
CIO 104 (8 outputs) is refreshed.
Refreshing Words in the Special I/O Unit Bit Area
The following example shows how to refresh 20 words from CIO 2000 to
CIO 2019 (I/O for Special I/O Units with unit numbers 0 to 1) when CIO 0.00
turns ON.
Name Label Operation
Error Flag ER ON if St is greater than E.
ON if St and E are in different memory areas.
OFF in all other cases.
IORF
2
4
0.00
St
E
St
E
IORF
104
104
St
E
0
15
0
15
St CIO 2
CIO 3
E CIO 4
CIO 104
CIO 2 and CIO 3
CIO 102 and CIO 103
CIO 4
CIO 104
(1)
(2)
(3)
I/O
refreshing
Processing
CPM1A Expansion I/O Units
St
E
0
15
St CIO 2000
CIO 2001
E CIO 2019
0.00
2000
2019
I/O
refreshing
Special I/O Units
Unit 0 Unit 1
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