Siemens SIMATIC S5-100U, Системное руководство

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Introduction to STEP 5 S5-100U
You can work with binary-coded decimals to program timers and counters in the decimal system.
BCD tetrads are defined in the range of 0 to 9.
Example: 12-bit timer or counter value in BCD and decimal formats
Figure 7-17. BCD and Decimal Formats
Word No.
Byte No.
Bit No.
Meaning
n
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
n+ 1 (low byte) n (high byte)
2
15
2
14
2
13
2
12
2
11
2
10
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 1 BCD No.
Decimal format
a a a a a
a a a a a
a a a a a
a a a a a
a a a a a
0
a a a a a
a a a a a
a a a a a
a a a a a
a a a a a
9
a a a a a
a a a a a
a a a a a
a a a a a
a a a a a
3
a a a a a
a a a a a
a a a a a
a a a a a
a a a a a
1
Table 7-6. Comparison of Number Formats
Decimal BCD Hexadecimal
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0000 0000
0000 0001
0000 0010
0000 0011
0000 0100
0000 0101
0000 0110
0000 0111
0000 1000
0000 1001
0001 0000
0001 0001
0001 0010
0001 0011
0001 0100
0001 0101 0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
Binary
7-32
EWA 4NEB 812 6120-02b