Mitsubishi Electric FX3G SERIES Programming Manual page 274

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Program example
1. Difference between ADD instruction and INC instruction caused by a program for adding "+1"
When ADD[P] is executed, "1" is added to the contents of D0 every time X001 turns from OFF to ON.
ADD[P] instruction is similar to INCP instruction described later except the contents shown in the table below:
Flag (zero, borrow or carry)
16-bit
operation
32-bit
operation
X001
FNC 20
ADDP
X001
FNC 24
INCP
272
ADD, ADDP, DADD or DADDP
+32767→0→+1→+2→
S +(+1)= D
←−2←−1←0←−32768
S D
+(−1)=
+2,147,483,647→0→+1→+2→
S D
+(+1)=
←−2←−1←0←−2,147,483,648
S D
+(−1)=
S S D
1 2
D 0 K 1 D 0
D 0
10 Arithmetic and Logical Operation (+, −, ×, ÷) – FNC 20 to FNC 29
instruction
Operates
+2,147,483,647→−2,147,483,648→−2,147,483,647
(D 0) + 1→(D 0)
(D 0) + 1→(D 0)
10.1 FNC 20 – ADD / Addition
INC, INCP, DINC, DINCP instruction
Does not operate
+32767→−32768→−32767
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