Omron CPM1 - PROGRAMING MANUAL 02-2001 Programming Manual page 370

Basic Ladder Diagrams
00000
00001
00002
00003 00004
00005
00006
352
When an INTERLOCK instruction is placed before a section of a ladder pro-
gram, the execution condition for the INTERLOCK instruction will control the
execution of all instruction up to the next INTERLOCK CLEAR instruction. If the
execution condition for the INTERLOCK instruction is OFF, all right-hand
instructions through the next INTERLOCK CLEAR instruction will be executed
with OFF execution conditions to reset the entire section of the ladder diagram.
The effect that this has on particular instructions is described in 7-11 INTER-
LOCK and INTERLOCK CLEAR – IL(02) and ILC(03).
Diagram B can also be corrected with an interlock. Here, the conditions leading
up to the branching point are placed on an instruction line for the INTERLOCK
instruction, all of lines leading from the branching point are written as separate
instruction lines, and another instruction line is added for the INTERLOCK
CLEAR instruction. No conditions are allowed on the instruction line for INTER-
LOCK CLEAR. Note that neither INTERLOCK nor INTERLOCK CLEAR re-
quires an operand.
00000
00001
00002
If IR 00000 is ON in the revised version of diagram B, above, the status of IR
00001 and that of IR 00002 would determine the execution conditions for
instructions 1 and 2, respectively. Because IR 00000 is ON, this would produce
the same results as ANDing the status of each of these bits. If IR 00000 is OFF,
the INTERLOCK instruction would produce an OFF execution condition for
instructions 1 and 2 and then execution would continue with the instruction line
following the INTERLOCK CLEAR instruction.
As shown in the following diagram, more than one INTERLOCK instruction can
be used within one instruction block; each is effective through the next INTER-
LOCK CLEAR instruction.
IL(02)
Address Instruction
00000 LD
00001 IL(02)
Instruction 1
00002 LD
Instruction 2
00003 Instruction 1
00004 LD
ILC(03)
00005 Instruction 2
00006 ILC(03)
IL(02)
Address Instruction
00000
Instruction 1
00001
00002
00003
IL(02)
00004
00005
Instruction 2
00006
00007
Instruction 3
00008
00009
Instruction 4
00010
00011
ILC(03)
00012
00013
Section
Operands
00000
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00001
00002
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Operands
LD 00000
IL(02)
LD 00001
Instruction 1
LD 00002
IL(02)
LD 00003
AND NOT 00004
Instruction 2
LD 00005
Instruction 3
LD 00006
Instruction 4
ILC(03)
6-3
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