222
Ladder Diagram Instructions
Section 5-8
5-8
Ladder Diagram Instructions
Ladder diagram instructions include ladder instructions and logic block
instructions and correspond to the conditions on the ladder diagram. Logic
block instructions are used to relate more complex parts.
5-8-1
LOAD, LOAD NOT, AND, AND NOT, OR, and OR NOT
Limitations
There is no limit to the number of any of these instructions, or restrictions in
the order in which they must be used, as long as the memory capacity of the
PC is not exceeded.
Description
These six basic instructions correspond to the conditions on a ladder diagram.
As described in
SECTION 4 Ladder-diagram Programming
, the status of the
bits assigned to each instruction determines the execution conditions for all
other instructions. Each of these instructions and each bit address can be
used as many times as required. Each can be used in as many of these
instructions as required.
The status of the bit operand (B) assigned to LD or LD NOT determines the
first execution condition. AND takes the logical AND between the execution
condition and the status of its bit operand; AND NOT, the logical AND
XFRB (@)
––
4
TRANSFER BITS
279
XNRW (@)
37
4
EXCLUSIVE NOR
375
XORW (@)
36
4
EXCLUSIVE OR
374
ZCP
––
4
AREA RANGE COMPARE
289
ZCPL
––
4
DOUBLE AREA RANGE COMPARE
290
+F (@)
––
4
FLOATING-POINT ADD
355
–F (@)
––
4
FLOATING-POINT SUBTRACT
357
*
F (@)
––
4
FLOATING-POINT MULTIPLY
358
/F (@)
––
4
FLOATING-POINT DIVIDE
359
Mnemonic
Code
Words
Name
Page
B
:
Bit
IR, SR, AR, HR, TIM/CNT, LR, TR
Ladder Symbols
Operand Data Areas
LOAD
LD
B
B
:
Bit
IR, SR, AR, HR, TIM/CNT, LR
LOAD NOT LD NOT
B
B
:
Bit
IR, SR, AR, HR, TIM/CNT, LR
AND AND
B
B
:
Bit
IR, SR, AR, HR, TIM/CNT, LR
AND NOT AND NOT
B
B
:
Bit
IR, SR, AR, HR, TIM/CNT, LR
OR OR
B
B
:
Bit
IR, SR, AR, HR, TIM/CNT, LR
OR NOT OR NOT
B
