Siemens NAN 67 Series Wartungshandbuch PDF herunterladen (Seite 290)

C-8

Ladder Logic (LAD) for S7-300 and S7-400

C79000-G7076-C504-02

The binary coded decimal (BCD) format represents a decimal number by

using groups of binary digits (bits). One group of 4 bits represents one digit

of a signed decimal number or the sign of the decimal number. The groups of

4 bits are combined to form a word (16 bits) or double word (32 bits). The

four most significant bits indicate the sign of the number (1111 indicates

minus and 0000 indicates plus). Commands with BCD-coded addresses only

evaluate the highest-value bit (15 in word, 31 in double word format).

Table C-7 shows the format and range for the two types of BCD numbers.

Figure C-5 and Figure C-6 provide an example of a binary coded decimal

number in word format and double word format, respectively.

Table C-7 Binary Coded Decimal Numbers with 16 and 32 Bits

Format Range

Word (16 bits, three-digit BCD number

with sign)

-999 to +999

Double word (32 bits, seven-digit BCD

number with sign)

-9,999,999 to +9,999,999

+310 (Decimal format)

0 0 0 0 0 0 1 1 0 0 0 1 0 0 0 0

03748111215

Bits

Sign

Hundreds

(10

)

Tens

(10

)

Ones

(10

)

Figure C-5 Binary Coded Decimal Number in Word Format

-9,999,999 (Decimal format)

1 0 0 1 1 0 0 1 1 0 0 1

037481112

Bits

Sign Hundreds

(10

)

Tens

(10

)

Ones

(10

)

Thousands

(10

)

Tens of

Thousands

(10

)

Hundreds of

Thousands

(10

)

Millions

(10

)

1 1 1 1

151619202324272831

1 0 0 11 0 0 11 0 0 11 0 0 1

Figure C-6 Binary Coded Decimal Number in Double Word Format

Binary Coded

Decimal Numbers

Number Notation

1 2 ... 285 286 287 288 289 290 291 292 293 294 295 ... 317 318

Kommentare zu diesen Handbüchern

Keine Kommentare

Siemens NAN 67 Series Wartungshandbuch Seite 290

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Kochfelder Siemens NAN 67 Series