Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 142

Sequence Input Instructions
3-2-13 CONDITION ON/OFF: UP(521) and DOWN(522)
Purpose
Ladder Symbols
Variations
Applicable Program Areas
Description
Flags
Precautions
The following table shows the operation of this program section.
Input bit status
CIO 0.00
1 1
1 1
1 0
0 1
1 0
0 1
0 0
0 0
UP(521) turns ON the execution condition for the next instruction for one cycle
when the execution condition it receives goes from OFF to ON. DOWN(522)
turns ON the execution condition for the next instruction for one cycle when
the execution condition it receives goes from ON to OFF.
UP(521)
DOWN(522)
Variations Creates ON Once for Upward Differentiation
Immediate Refreshing Specification
Variations Creates ON Once for Downward Differentiation
Immediate Refreshing Specification
Block program areas
OK OK
UP(521) is placed between an execution condition and another instruction to
turn the execution condition into an up-differentiated condition. UP(521)
causes the connecting instruction to be executed just once when the execu-
tion condition goes from OFF to ON.
DOWN(522) is placed between an execution condition and another instruction
to turn the execution condition into a down-differentiated condition.
DOWN(522) causes the connecting instruction to be executed just once when
the execution condition goes from ON to OFF.
The DIFU(013) and DIFD(014) instructions can also be used for the same
purpose, but they require work bits. UP(521) and DOWN(522) simplify pro-
gramming by reducing the number of work bits and program addresses
needed.
There are no flags affected by UP(521) and DOWN(522).
UP(521) and DOWN(522) are intermediate instructions, i.e., they cannot be
used as right-hand instructions. Be sure to program a right-hand instruction
after UP(521) or DOWN(522).
CIO 0.01 CIO 0.02
1
0
1
1
0
0
1
0
Step program areas Subroutines
OK
Section 3-2
Output bit status
CIO 0.03
0
0
1
0
1
1
1
1
UP(521)
Not supported
UP(522)
Not supported
Interrupt tasks
OK
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