Mitsubishi Electric MELSEC-Q/L - Page 229

6 BASIC INSTRUCTIONS
6.2 Arithmetic Operation Instructions
227
6
■D-
• Subtracts 32-bit BIN data designated by (S1) from 32-bit BIN data designated by (S2) and stores the result of the
subtraction at the device designated by (D).
• The values for (S1), (S2) and (D) can be designated at between -2147483648 and 2147483647 (BIN 32 bits).
• Judgment of whether the data is positive or negative is made on the basis of the most significant bit (b31).
• The following will happen when an underflow or overflow is generated in an operation result: The carry flag (SM700) in this
case does not turn ON.
Operation error
• There is no operation error in the D+(P) or D-(P) instruction.
Program example
• The following program adds 28-bit data from X10 to X2B to the data at D9 and D10 when X0 goes ON, and outputs the
result of the operation to Y30 to Y4B.
• The following program subtracts the data from M0 to M23 from the data at D0 and D1 when XB goes ON, and stores the
result at D10 and D11.
•0  Positive
•1  Negative
[Ladder Mode] [List Mode]
[Ladder Mode] [List Mode]
123456 (BIN)
b0b16 b15
+1
567890 (BIN)
b31
+1
444434 (BIN)
+1
S1 S2
D
S1 S2
D
b0b16 b15b31 b0b16 b15b31
Since bit 31 value is "0",
result of operation takes a positive value.
Since bit 31 value is "1",
result of operation takes a negative value.
K 2147483648
(80000000H)
K2147483647
(7FFFFFFFH)
K2
(00000002
H)
K2
(FFFFFFFEH)
K214748364
6
K 214748364
7
(80000001H)
(7FFFFFFEH)
Step
Instruction
Device
Step
Instruction
Device