Yaskawa YASNAC PC NC PLC Programming Manual - Manual (Page 64)

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YASNAC PCNC PLC Programming Manual Chapter 6: PLC Instructions
(c) Explanation
• A ST contact must be entered before the ADD instruction.
• The ADD instruction is executed in intervals of “4 × n” msec while the ST contact is
ON.
• There is no function to detect overflow. Make sure that the result will not exceed 255
(FFH).
(d) Example
(16)SUB (SUB Register) RR after operation: RR-
(a) Function
The function executes subtraction between the content in the resister R2 and the content in
register R1 when the R1 contact is ON (RR = 1) and stores the result to register R2.
The content in register R1 remains unchanged and status of RR also remains unchanged.
If the ST contact is OFF (RR = 0), the instruction is not executed.
(b) Format
(c) Explanation
There is no function to detect underflow. Make sure that the following is always satisfied:
R1
≤
R2.
(17)ANR (AND Register) RR after operation: RR-
(a) Function
The function executes AND operation between the content in the resister R2 and the
content in register R1 when the ST contact is ON (RR = 1) and stores the result to
register R2.
The content in register R1 remains unchanged and status of RR also remains unchanged.
If the ST contact is OFF (RR = 0), the instruction is not executed.
A B Paradym31 Variable Name