Delta Electronics AC Motor Drive VFD-E User Manual page 335

Appendix D How to Use PLC Function|
Explanations:
1. See the specifications of each model for their range of use.
2. This instruction adds S1 and S2 in BIN format and store the result in D.
3. The highest bit is symbolic bit 0 (+) and 1 (-), which is suitable for algebraic addition, e.g.
3 + (-9) = -6.
4. Flag changes in binary addition
16-bit command:
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 1:
16-bit command:
When X0 = On, the content in D0 will plus the content in D10 and the sum will be stored in D20.
Remarks:
Flags and the positive/negative sign of the values:
16 bit: Zero flag
-2, -1, 0
Borrow flag
32 bit: Zero flag
-2, -1, 0 -2,147,483,648
Borrow flag
D-52
X0
ADD
-32,768
The highest bit
of the data
= 1 (negative)
The highest bit
of the data
= 1 (negative)
D0 D10
Zero flag
-1, 0 1
The highest bit
of the data
= 0 (positive)
Zero flag
-1, 0 1
The highest bit
of the data
= 0 (positive)
Revision June 2008, 04EE, SW--PW V1.11/CTL V2.11
D20
Zero flag
32,767 0 1 2
Carry flag
Zero flag
2,147,483,647 0 1 2
Carry flag