Rockwell Automation 2711 ControlNet Communications User Guide - Manual (Page 20)

ControlNet Communications 20
Publication 2711-6.10
PLC
Acronym for Programmable Logic Controller identified by the 1785-
Catalog number prefix.
Repeater
Two-port component that receives and transmits all data from one
segment to another segment.
RIO
Acronym for Remote Input Output. An Allen-Bradley proprietary
master-slave communication protocol.
Scheduled Messages
Messages that occur at a regular specified interval. Scheduled
messages are assigned a particular portion of the network update
time (NUT) and are always transmitted at that time.
Segment
Trunk-cable sections connected through taps with terminators at each
end and no repeaters.
SMAX
Highest ControlNet node address which can communicate during the
scheduled portion of the network update interval.
Tap
Hardware component that connects devices to the ControlNet trunk
cable.
Trunk Cable
Bus or central part of a cable system.
UMAX
Highest ControlNet node address which can communicate during the
unscheduled portion of the network update interval.
Unscheduled Messages
Messages that are sent on an as needed basis. Unscheduled messages
are sent during the unscheduled portion of the Network update
interval.