Omron SYSMAC C20K Operation Manual page 88

Bit Control Instructions
5-6-3 KEEP – KEEP(11)
Description
0002 0003
0500
0002
0003
Flags
Ladder Symbol
S
KEEP(11)
R
KEEP(11) is used to maintain the status of the designated bit based on two
execution conditions. These execution conditions are labeled S and R. S is
the set input; R, the reset input. KEEP(11) operates like a latching relay that
is set by S and reset by R.
When S turns ON, the designated bit will go ON and stay ON until reset, re-
gardless of whether S stays ON or goes OFF. When R turns ON, the desig-
nated bit will go OFF and stay OFF until reset, regardless of whether R stays
ON or goes OFF. The relationship between execution conditions and
KEEP(11) bit status is shown below.
S execution condition
R execution condition
Status of B
Notice that KEEP(11) operates like a self-maintaining bit. The following two
diagrams would function identically, though the one using KEEP(11) requires
one less instruction to program and would maintain status even in an inter-
locked program section.
S
R
There are no flags affected by this instruction.
Operand Data Areas
B
Address Instruction
0500
0000 LD
0001 OR
0002 AND NOT
0003 OUT
Address Instruction
KEEP(11)
0000 LD
0500
0001 LD
0002 KEEP(11)
Section 5-6
B: Bit
IR, HR
Operands
0002
0500
0003
0500
Operands
0002
0003
0500
77