Rockwell Automation 1772-LV Mini-PLC - 2/15 Programmable Controller (Series B) Programming and Operations - Manual (Page 209)

Glossary
Appendix B
BĆ16
Series
A hardware design change which affects the form, fit, and/or function of a unit
or module. In Allen-Bradley PCs, this is indicated by the word series and a
letter following the catalog number (e.g., cat. no. 1774-DL2, series B).
Solenoid
A electromagnet with a movable core, or plunger, which, when it is energized,
can move a small mechanical part a short distance.
State
The logic “0” or “1” condition in PC memory or at a circuit’s input or output.
Static
Refers to a state in which a quantity does not change appreciably within an
arbitrarily long time interval.
Storage
Synonymous with memory.
Switching
The action of turning on and off a device.
System
A collection of units combined to work as a larger integrated unit having the
capabilities of all the separate units.
Terminal
Any fitting attached to a circuit or device for convenience in making electrical
connections.
Terminal Address
An Allen-Bradley 5-digit number which identifies a single I/O terminal. It is
also related directly to a specific image table bit address.
Thumbwheel Switch
A rotating numeric switch used to input numeric information to a controller.
Timer
In relay-panel hardware, an electromechanical device which can be wired and
present to control the operating interval of other devices. In PC, a timer is
internal to the processor, which is to say it is controlled by a user- programmed
instruction. A timer instruction has greater capability than a hardware timer.
Therefore, most PC applications generally use timer instructions.
Tolerance
A specified allowance for error from a desired or measured quantity.
True
A related to PC instructions, an enabling logic state.