D - glossary, Glossary – Rockwell Automation 1775-S4B,D17756.5.3 User Manual SCANNER/MSG HND User Manual
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Appendix
D
DĆ1
Glossary
Address: An expression preceded by a dollar sign that
represents where data is stored.
ASCII: American Standards Code for Information
Interchange. It is an 8-bit (7 bits plus a parity bit) code for
representing alphanumerics, punctuation marks, and control
code characters.
Baud: A rate of communication equal to the number of code
elements (bits) per second.
BCD: Abbreviation for Binary Coded Decimal. A method used
to express individual decimal digits (0 thru 9) in 4-bit binary
notation.
Binary
BCD
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
0
1
2
3
4
5
6
7
8
9
Binary: A numbering system using only the digits 0 and 1.
Also called ”base 2”.
Bit:
1) Binary digit. The smallest unit of information in the
binary numbering system. Represented by the digits 0 and 1.
2) The smallest division of a PLC-3 memory word.
Byte: Equals 8 bits.
Channel: A designated path for a signal.
Character: One symbol of a set of elementary symbols such as
a letter of the alphabet or a decimal numeral.
Command: A task initiated by a user that tells the 1775-S4B
module what to do.