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Description
KEEP(11) is used to maintain the status of the designated bit based on two exe-
cution 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
KEEP(11) operates like the self-maintaining bit described in 4-8-3 Self-maintain-
ing Bits. 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 interlocked program section.
00002
00003
00500
00002
00003
00500
S
R
KEEP(11)
B
Address
Instruction
Operands
Address
Instruction
Operands
00000
LD
00002
00001
OR
00500
00002
AND NOT
00003
00003
OUT
00500
00000
LD
00002
00001
LD
00003
00002
KEEP(11)
00500
Flags
There are no flags affected by this instruction.
Precautions
Exercise caution when using a KEEP reset line that is controlled by an external
normally closed device. Never use an input bit in an inverse condition on the re-
set (R) for KEEP(11) when the input device uses an AC power supply. The delay
in shutting down the PC’s DC power supply (relative to the AC power supply to
the input device) can cause the designated bit of KEEP(11) to be reset. This situ-
ation is shown below.
A
Input Unit
A
NEVER
S
R
KEEP(11)
B
Bits used in KEEP are not reset in interlocks. Refer to the 5-10 INTERLOCK –
and INTERLOCK CLEAR IL(02) and ILC(03) for details.
Bit Control Instructions
Section 5-9
Содержание SYSMAC C200HS
Страница 1: ...Cat No W235 E1 05 C200HS SYSMAC Programmable Controllers...
Страница 2: ...C200HS Programmable Controllers Operation Manual Revised February 2002...
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Страница 379: ...371 SR word Corresponding key s Bit 279 03 04 05 3 06 07 VER 08 09 Monitoring Operation and Modifying Data Section 7 1...
Страница 470: ...468 Programmer Program Date Page Word Contents Notes Word Contents Notes Data Storage...
Страница 471: ...469 Programmer Program Date Page TC address T or C Set value Notes TC address T or C Set value Notes Timers and Counters...