Preface
P–4
Publication 17706.5.20 - June 1997
network address—the network address of a node on the ControlNet
cable system. This address must be in the range of 1 to 99 (decimal)
and be unique to that subnet. A subnet can contain a maximum of
99 nodes.
node—any physical device connecting to the ControlNet cable
system that requires a network address in order to function on the
network.
NUT
(network update time)—the rate at which access to the
network is granted
parallel port—input/output port for a device that transmits multiple
data and control bits over wires connected in parallel
PCCC (Programmable Controller Communications
Commands)—an Allen-Bradley communication protocol used on
the Data Highway Plus network
repeater—a two-port active physical layer component that
reconstructs all traffic it hears on one network segment side and
retransmits it to another network segment side. Repeaters allow for
extensions in network distance, conversion to alternate media
(coaxial cable, fiber, etc.) and altering the topology of the network.
RIO (Remote Input/Output)—an Allen-Bradley remote
input/output link that supports remote, time-critical, I/O and control
communication between a master PLC controller and its remote I/O
and adapter mode slave processors
RS-232C port—a serial port that complies with accepted industry
standards for serial communications connections
segment—trunkline sections connected via taps with terminators at
each end, and with no repeaters