GE Dash 3000, Service Manual

Page: 53 / 292

Revision A Dash 3000/4000 Patient Monitor 3-9
2000966-339
Installation: Optional Ethernet Communication
Segment and Branch
Some Ethernet systems are comprised of smaller, stand-alone Ethernet
systems (called branches or segments) that are connected by bridges,
concentrators, or repeaters. Many nodes on the Ethernet network may be
serviced by one segment or branch. Each segment may support many
patient monitors, central stations, and auxiliary devices.
For example, one segment may connect all the patient monitors and
central stations in the ICU (Intensive Care Unit) and another may
connect the monitoring system in the CCU (Critical Care Unit). Each
segment could be a fully-functioning stand-alone system if they were not
connected to each other. However, with a bridge or repeater to connect
the ICU (one segment) with the CCU (the other segment), information
can pass between any of the nodes (patient monitors and central
stations) on either branch similar to a patient transfer from one unit to
another.
A section is a single length of twisted pair cable with a RJ-45 connector
on each end. A section goes from one twisted pair transceiver to the
concentrator. A segment is comprised of all the sections of twisted pair
cable connected in a star formation to one concentrator.
Repeater
A repeater is used to extend the length of cabling when the distance
required exceeds the length of the cable specifications. It is simply a
transceiver that passes all network data between any two segments.
Note that the repeater passes all network data between the two
segments, regardless of whether or not the one node is sending data to
another node on the same segment.
Bridge
A bridge is more selective than a repeater with the data that it passes
between segments. It also acts as a transceiver between two segments,
but it only passes signals if a node on one of the segments is attempting
to communicate with a node on the other segment. Since the majority of
communication on the network occurs within a single segment, the
bridge does not pass all of the data from one segment to the other. This
lowers the amount of data traffic passing between segments, and makes
the network more efficient than a system that is connected with
repeaters.