7-8
Section
Bit Control Instructions
379
In the second example (Diagram B), IR 10000 will be turned ON when IR 00001
goes ON and will remain ON (even if IR 00001 goes OFF) until IR 00002 goes
ON.
00000
Diagram A
00002
RSET 20000
Diagram B
SET 20000
00001
Address
Instruction
Operands
00000
LD
00000
00001
OUT
20000
Address
Instruction
Operands
00000
LD
00001
00001
SET
20000
00002
LD
00002
00003
RSET
20000
20000
7-8-3 KEEP – KEEP(11)
B
: Bit
IR, SR, AR, HR, LR
Ladder Symbol
Operand Data Areas
S
R
KEEP(11)
B
Any output bit can generally be used in only one instruction that controls its sta-
tus.
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, regard-
less of whether S stays ON or goes OFF. When R turns ON, the designated 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
Flags
There are no flags affected by this instruction.
Limitations
Description