Byte, word, doubleword relationship

bit The bit

byte byte

word word

double word Two words

Integer Integers

Real number The set of real Numbers

Floating-point number Floating point numbers

1double word = 2 word

1 word = 2 byte

1 byte =8 bit

for example ：

VB100= VB100.7~ VB100.0   （ High position Low position ）

VW100= VB100  VB101     （ High position Low position ）

VD100= VW100  VW102 = VB100 VB101 VB102 VB103  （ High position Low position ）

for example ：

MB516 from M516.0~M516.7 form , because M516.3 by 1, therefore MB516 The binary representation of is 0000 1000, So its decimal value is 8.
MW516 from MB516,MB517 form , Because Siemens is different from other manufacturers , Large tail storage mode is adopted , therefore MW516 The content of is 0000 1000 0000 0000, Its decimal number is 2048.
MD516 from MW516 and MW518 form ,MW516 from MB516 and MB517 form ,MW518 from MB518 and MB519 form ,MD516 The content of is 0000 1000 0000 0000 0000 0000 0000 0000, Its decimal number is 134217728.

Chart ：

DWORD		DW0	12345678
WORD		WORD0	1234
		WORD2	5678
BYTE		BYTE0	12
		BYTE1	34
		BYTE2	56
		BYTE3	78

BYTE0		BIT31	BIT30	BIT29	BIT28	BIT27	BIT26	BIT25	BIT24
		0	0	0	1	0	0	1	0
BYTE1		BIT23	BIT22	BIT21	BIT20	BIT19	BIT18	BIT17	BIT16
		0	0	1	1	0	1	0	0
BYTE2		BIT15	BIT14	BIT13	BIT12	BIT11	BIT10	BIT9	BIT8
		0	1	0	1	0	1	1	0
BYTE3		BIT7	BIT6	BIT5	BIT4	BIT3	BIT2	BIT1	BIT0
		0	1	1	1	1	0	0	0