Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual - Manual (Page 431)

Glossary
Appendix D
D-12
Ladder Diagram
An industry standard for representing control systems.
Ladder Diagram Programming
A method of writing a user program in a format similar to a relay
ladder diagram.
Language
A set of symbols and rules used for representing and
communicating information.
Latching Relay
A relay that maintains a given position by mechanical or electrical means
until released mechanically or electrically.
Leading Edge One-Shot
A programming technique that sets a bit for one scan when its input
condition has made a false-to-true transition. The false-to-true transition
represents the leading edge of the input pulse.
Least Significant Bit (LSB)
The bit that represents the smallest value in a nibble, byte, or word.
Least Significant Digit (LSD)
The digit that represents the smallest value in a byte or word.
LED
Light-Emitting Diode.
LED Display
An illuminated visual readout composed of alphanumeric character
segments.
Limit Switch
An electrical switch actuated by some part and/or motion of a machine
or equipment.
Line
(1) A component part of system used to link various subsystems located
remotely from the processor. (2) The source of power for operation.
Example: 120V ac line.
Liquid Crystal Display (LCD)
A reflective visual readout of alphanumeric characters. Since its character
segments are displayed only by reflected light, it has extremely low power
consumption. Contrasted with LED Display, which emits light.
L