Subtraction - Delta Electronics AC Motor Drive VFD-E User Manual

API Mnemonic
21 SUB
Type Bit Devices
OP
X Y
S
1
S
2
D
Operands:
S1: Minuend S2: Subtrahend
Explanations:
1. This instruction subtracts S1 and S2 in BIN format and stores the result in D.
2. The highest bit is symbolic bit 0 (+) and 1 (-), which is suitable for algebraic subtraction.
3. Flag changes in binary subtraction
In 16-bit instruction:
A. If the operation result ＝ 0, zero flag M1020 = On.
B. If the operation result ＜ -32,768, borrow flag M1021 = On.
C. If the operation result ＞ 32,767, carry flag M1022 = On.
Program Example:
In 16-bit BIN subtraction:
When X0 = On, the content in D0 will minus the content in D10 and the remainder will be stored in
D20.
Revision June 2008, 04EE, SW--PW V1.11/CTL V2.11
Operands
P S , S , D
1 2
Word devices
M K H KnX KnY KnM T
* * *
* * *
D: Remainder
X0
SUB
Appendix D How to Use PLC Function|
C D
* * * *
* * * *
* * * *
D0 D10
Function

Subtraction

Program Steps
SUB, SUBP: 7 steps
DSUB, DSUBP: 13 steps
*
*
*
D20
D-53