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Sequence Input Instructions Section 3-3
Applicable Program Areas
Description AND LD connects in parallel the logic block just before this instruction with
another logic block.
The logic block consists of all the instructions from a LOAD or LOAD NOT
instruction until just before the next LOAD or LOAD NOT instruction on the
same rungs.
The following diagram requires an OR LOAD instruction between the top logic
block and the bottom logic block. An ON execution condition would be pro-
duced either when CIO 000000 is ON and CIO 000001 is OFF or when
CIO 000002 and CIO 000003 are both ON. The operation of and mnemonic
code for the OR LOAD instruction is exactly the same as those for a AND
LOAD instruction except that the current execution condition is ORed with the
last unused execution condition.
Flags There are no flags affected by this instruction.
Precautions Three or more logic blocks can be connected in parallel using this instruction
to first connect two of the logic blocks and then to connect the next and subse-
quent ones in order. It is also possible to continue placing this instruction after
three or more logic blocks and connect them together in parallel.
When a logic block is connected by AND LOAD or OR LOAD instructions, the
total number of AND LOAD/OR LOAD instructions must match the total num-
ber of LOAD/LOAD NOT instructions minus 1. If they do not match, a pro-
gramming error will occur.
Example
Block program areas Step program areas Subroutines Interrupt tasks
OK OK OK OK
LD
LD
OR LD
to
to
Logic block A
Logic block B
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