Allen-Bradley MicroLogix 1200 User Manual page 153

Glossary 9
run mode
This is an executing mode during which the controller scans or
executes the ladder program, monitors input devices, energizes output
devices, and acts on enabled I/O forces.
rung
Ladder logic is comprised of a set of rungs. A rung contains input and
output instructions. During Run mode, the inputs on a rung are
evaluated to be true or false. If a path of true logic exists, the outputs
are made true. If all paths are false, the outputs are made false.
save
To upload (transfer) a program stored in memory from a controller to
a personal computer; OR to save a program to a computer hard disk.
scan time
The time required for the controller to execute the instructions in the
program. The scan time may vary depending on the instructions and
each instruction's status during the scan.
sinking
A term used to describe current flow between an I/O device and
controller I/O circuit — typically, a sinking device or circuit provides a
path to ground, low, or negative side of power supply.
sourcing
A term used to describe current flow between an I/O device and
controller I/O circuit — typically, a sourcing device or circuit provides
a path to the source, high, or positive side of power supply.
status
The condition of a circuit or system, represented as logic 0 (OFF) or 1
(ON).
terminal
A point on an I/O module that external I/O devices, such as a push
button or pilot light, are wired to.
throughput
The time between when an input turns on and the corresponding
output turns on.
Publication 1762-UM001D-EN-P - March 2004