Nematron Pointe Controller - Manual (Page 105)

Pointe Controller User Guide Chapter 4: System Design and Installation
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4.11 Ethernet Connection Guide
Ethernet 10Base-T is a flexible, low cost method of cabling local area networks.
Pointe Controller units must be connected using 10Base-T compatible products.
All Ethernet 10Base-T implementation details are defined by the EIA/TIA standard
568A. This standard specifies UTP, an acronym for Unshielded Twisted Pair cable,
to be between all nodes on a given 10Base-T network. UTP cables are rated
according to their data-carrying ability (bandwidth) and rated by “category”
number. The standard specifies category 3, 4, or 5 cable may be used with
Ethernet 10Base-T applications. IEEE Ethernet standards limit cable length
between nodes to 100 meters (328 feet). The distance limitation is based on the
maximum cable signal loss of 11.5 decibels between the source and destination.
Due to emerging high speed standards and product capabilities, many sites now
install UTP category 5 type cables exclusively. We recommend category 5 cable for
all Pointe Controller connections.
4.11.1 UTP Cable Characteristics
Cabling is the foundation of any network; if it’s incorrect or unstable all other
communications characteristics will be unreliable. The most critical aspect of UTP
cabling is the maintaining of correct conductor pairing throughout the network.
Commonly four-pair (8 wire) 24 AWG thermoplastic insulated solid conductor
wire with a 100 ohm impedance and total diameter of less than 6.35mm (0.25
inch) should be used with Ethernet 10Base-T networks. To ensure correct pairing,
network vendors offer patch cables (straight-through and crossover) which are
assembled with connectors.
4.11.2 Cable Connectors
Pointe Controller units interface the network via the standard 8-pin extension
port compatible with RJ45 type connectors. RJ45 type connectors are designed to
accommodate rounded PVC outer jacket UTP cable. The strain relief for the cable
is provided by the part of the RJ45 connector that acts as a wedge against the
outer jacket. The wedge is pressed and locked tightly against the cable jacket
when the connector is crimped into place.
A 10Base-T RJ45 connection is shown below: