Delta Electronics VFD037CH23A-21 — основы работы с флагами и вычитанием в PLC системах [511/638]

Превью страниц Страница 511 / 638
Delta Electronics VFD037CH23A-21 Руководство по эксплуатации онлайн [511/638] 460294
Chapter 16 PLC Function CH2000 Series
16-58
Remarks
Flags and the positive/negative sign of the values:
-2, -1, 0 -32,768 -1, 0 1 32,767 0 1 2
-2, -1, 0 -2,147,483,648
-1, 0 1
2,147,483,647 0 1 2
16 bit: Zero flag
Zero flag
Zero flag
Borrow flag
The highest bit
of the data
= 1 (negative)
32 bit: Zero flag
Zero flag
Zero flag
The highest bit
of the data
= 0 (positive)
Carry flag
Borrow flag
Carry flag
The highest bit
of the data
= 1 (negative)
The highest bit
of the data
= 0 (positive)
API
21
D
SUB
P
S1 S2 D
Subtraction
Bit Devices Word Devices
X Y M K H KnX KnY KnM T C D
S
1
S
2
D
Operands: None
16-bit
command (7 STEPS)
SUB SUBP
32-bit
command (13 STEPS)
Flag signal: M1020 Zero flag
M1021 Borrow flag
M1022 Carry flag
Explanation
1.
S
1
: Minuend S
2
: Subtrahend D: Remainder
2. This instruction subtracts S
1
and S
2
in BIN format and stores the result in D.
3. The highest bit is symbolic bit 0 (+) and 1 (-), which is suitable for algebraic
subtraction.
4. Flag changes in binary subtraction
In 16-bit instruction:
If the operation result 0, zero flag M1020 = On.
If the operation result -32,768, borrow flag M1021 = On.
If the operation result 32,767, carry flag M1022 = On.
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.
X0
D0 D10
D20
SUB

Содержание

1610

Изучите основы работы с флагами и вычитанием в PLC системах. Понимание знаков и флагов поможет в эффективной работе с данными и командами.