Fnc 21 - Sub / Subtraction - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
10.2 FNC 21 – SUB / Subtraction
Outline
This instruction executes subtraction using two values to obtain the result (A − B = C).
1. Instruction format
FNC 21
D P
SUB
2. Set data
Operand type
S
1
S
2
D
3. Applicable devices
Bit Devices
Oper-
and System User
Type
X Y M T C S D .b KnX KnY KnM KnS T C D R U \G
S
1
S
2
D
: This function is supported only in FX
Explanation of function and operation
1. 16-bit operation (SUB and SUBP)
The contents of
S
Command
input
FNC 21
SUB
• The most significant bit of each data indicates the sign (positive: 0 or negative: 1), and data is subtracted
algebraically.
5 − (−8) = 13
• When a constant (K) is specified in
2. 32-bit operation (DSUB and DSUBP)
The contents of [
is transferred to [
Command
input
FNC 21
DSUB
• The most significant bit of each data indicates the sign (positive: 0 or negative: 1), and data is subtracted
algebraically.
5500 − (−8540) = 14040
• When a constant (K) is specified in [
format.
→ For the floating point subtraction instruction ESUB (FNC121), refer to Section 18.9.
Mnemonic
16-bit Instruction
7 steps SUB
SUBP
Data for subtraction or word device number storing data
Data for subtraction or word device number storing data
Word device number storing the subtraction result
Digit Specification
/FX
3U 3UC
are subtracted from
S
2 1
S S D
1 2
S or
1
S +1, S ] are subtracted from [
2 2
D +1, D ].
1 1
S S D
1 2
S +1,
1
10 Arithmetic and Logical Operation (+, −, ×, ÷) – FNC 20 to FNC 29
Operation Condition
32-bit Instruction
Continuous
13 steps
Operation
Pulse (Single)
Operation
Description
Word Devices
Special
System User Index
Unit
V Z Modify K H
PLCs.
in binary format, and the subtraction result is transferred to
S S D
− →
1 2
S , it is automatically converted into binary format.
2
S +1, S ] in binary format, and the subtraction result
1 1
S S S
] − [
[ +1,
1 1 2
S ] or [ S +1, S ], it is automatically converted into binary
1 2 2
10.2 FNC 21 – SUB / Subtraction
Mnemonic Operation Condition
Continuous
DSUB
Operation
Pulse (Single)
DSUBP
Operation
Data type
16- or 32-bit binary
16- or 32-bit binary
16- or 32-bit binary
Others
Con- Real Charac-
stant Number ter String
E " "
S D D
] → [
+1, +1,
2
1
2
3
4
5
Pointer
P
6
.
D
7
8
9
]
10
273