Innotech Device Network Cabling - Manual (Page 38)

© Mass Electronics Pty Ltd 2007
Innotech Device Network Cabling Installation Instructions
Edition 3.0 dated 05.12.2013 Page 38
4-1 Network Specifications
The network type and baud rate determine the maximum recommended cable specifications. For
cable runs longer than the recommended lengths an Innotech Repeater IR11 or IR12 should be used.
Repeaters may also be required if the number of devices connected to a network segment exceeds
the maximum allowable number of devices for the specific network.
Network
Type
Maximum
Number of
Devices
Maximum Number of
Devices Before a Repeater
is Required
Baud Rate
Maximum Cable
Length Before
Repeater is Required
Primary
Network
128 31
9600/4800 1000m
57600/38400 400m
Sub System
Network
63 31 115200 200m
REM
Network
15 N/A 38400 600m
Table 4-1: Repeater Requirements
4-2 Cable Specifications
Innotech recommends the use of cables specifically designed for RS485 networks. There are many
cables on the market that meet the specifications for RS485 networks.
Best reliability is achieved through a cable consisting of 2 individually shielded twisted pairs of low
capacitance. Such cables also provide excellent mechanical strength and lowest electrical resistance,
which is beneficial for maximum length cable runs.
Some CAT6 cable types may also be suitable in certain applications. Care should be taken when using
CAT6 for Primary Networks as they frequently omit shielding. CAT6 cables should be shielded in order
to provide reliable communications.