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The following diagram requires AND LOAD to be converted to mnemonic code
because three pairs of parallel conditions lie in series. The two options for coding
the programs are also shown.
00000 00002 00004
00001 00003 00005
00500
Address Instruction Operands Address Instruction Operands
00000 LD 00000
00001 OR NOT 00001
00002 LD NOT 00002
00003 OR 00003
00004 AND LD —
00005 LD 00004
00006 OR 00005
00007 AND LD —
00008 OUT 00500
00000 LD 00000
00001 OR NOT 00001
00002 LD NOT 00002
00003 OR 00003
00004 LD 00004
00005 OR 00005
00006 AND LD —
00007 AND LD —
00008 OUT 00500
Again, with the method on the right, a maximum of eight blocks can be com-
bined. There is no limit to the number of blocks that can be combined with the
first method.
The following diagram requires OR LOAD instructions to be converted to mne-
monic code because three pairs of series conditions lie in parallel to each other.
00000 00001
00002 00003
00040 00005
00501
The first of each pair of conditions is converted to LOAD with the assigned bit
operand and then ANDed with the other condition. The first two blocks can be
coded first, followed by OR LOAD, the last block, and another OR LOAD; or the
three blocks can be coded first followed by two OR LOADs. The mnemonic
codes for both methods are shown below.
00000 LD 00000
00001 AND NOT 00001
00002 LD NOT 00002
00003 AND NOT 00003
00004 OR LD —
00005 LD 00004
00006 AND 00005
00007 OR LD —
00008 OUT 00501
00000 LD 00000
00001 AND NOT 00001
00002 LD NOT 00002
00003 AND NOT 00003
00004 LD 00004
00005 AND 00005
00006 OR LD —
00007 OR LD —
00008 OUT 00501
Address Instruction Operands Address Instruction Operands
Again, with the method on the right, a maximum of eight blocks can be com-
bined. There is no limit to the number of blocks that can be combined with the
first method.
Basic Ladder Diagrams Section 4-4