Rockwell Automation 1772-LV Mini-PLC - 2/15 Programmable Controller (Series B) Programming and Operations - Manual (Page 196)

Glossary
Appendix B
BĆ3
Byte
A sequence of binary digits usually operated upon as a unit. (The exact number
depends on the system.) In Allen-Bradley PCs, this is the smallest complete
unit of information that can be transmitted, and is made up of 8 data bits plus a
parity bit.
Cascading
A programming technique that extends the ranges of timer and/or counter
instructions beyond the maximum values that may be accumulated. This is
accomplished by means of other PC instructions.
Cassette Recorder
A peripheral device for transferring information between PC memory and
magnetic tape. In the record mode it is used to make a permanent record of a
program existing in the processor’s memory. In the playback mode it is used to
enter a previously recorded program into the processor’s memory.
Cassette Tape
A magnetic recording tape permanently enclosed in a protective housing. The
Philips type cassette is most common. Cassettes for PC use should contain
computer grade tape.
Catalog Number (cat. no.)
A designation for a specific Allen-Bradley PC unit with the major product line.
It is a 4-digit number generally followed by a dash and 2 or three alphanumeric
characters.
Central Processing Unit (CPU)
Another term for processor. It includes the circuits controlling the interpretation
and execution of the user-inserted program instructions stored in the PC
memory.
Chassis
The piece of hardware that the processor and its associated modules set into
when operating.
Character
One symbol of set of elementary symbols, such as a letter of the alphabet or a
decimal numeral.
Clear
To return a memory to a non-programmed state, usually represented as “0” or
off.