Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 452)

Appendix B
Number Systems, Hex Mask
B–4
Example: BCD bit pattern 0111
2,
for one digit, has a decimal equivalent
value of 7:
1 0 1 1
1x2 0 = 1
1x2 1 = 2
1x2 2 = 4
0x2 3 = 0
1
2
4
0
7
+
To form multiple digit numbers, BCD uses a 16–bit pattern similar to binary.
This allows up to 4 digits, using the above 4–bit binary code. BCD numbers
have a range of 0 to 32,767 in the SLC 500 family processors.
The following figure shows the BCD representation for the decimal number
9862:
Position Values
0 1 0 1 0 1 0 0 1 0 1 0 0 0 1 0
9 8 6 2
Binary Pattern
Thousands Hundreds Tens Ones
8 4 2 1 8 4 2 1 8 4 2 1 8 4 2 1
Decimal value
Hexadecimal numbers use single characters 0 to 9 and A to F, to represent
decimal values ranging from 0 to 15:
1 0 2 3 5 4 6 7 9 8 A B D C E F
1 0 2 3 5 4 6 7 9 8 10 11 13 12 14 15
HEX
Decimal
The position values of hexadecimal numbers are powers of 16, beginning
with 16
0 at the right:
16 3 16 2 16 1 16 0
Example: Hexadecimal number 218A has a decimal equivalent value of
8586:
1 2 8 A
10x16 0 = 10
8x16 1 = 128
1x16 2 = 256
2x16 3 = 8192
10
128
256
8192
8586
Hexadecimal Numbers