Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 225)

Appendix
A
AĆ1
Glossary
Absolute Dimension: A dimension expressed with respect to the initial
zero point of a coordinate axis.
Accumulator Register: A register that accumulates the axis feed
increments to indicate the current commanded position for the axis to
follow.
Adapter Module: A module that provides communication between an
I/O chassis and the PC processor. It transmits I/O chassis input
information to, and receives output information from, the processor.
Amplifier: A signal gain device whose output is a function of its input.
Analog: An expression of values that can vary continuously between
specified limits.
Axis: A principal direction along which a movement of the tool or
workpiece occurs.
Backlash: A relative movement between interacting mechanical parts,
resulting from looseness.
Binary: A base 2 numbering system.
Binary Coded Decimal (BCD): A numbering system used to express
individual decimal digits (0 thru 9) in four-bit binary notation.
Bit: Binary digit. The smallest unit of information. Represented by the
digits 0 and 1. The smallest division of a PC word.
Block: A set of words handled as a unit.
Clear: To erase the contents of a storage device by replacing the contents
with zeros.