Innotech Omni C14, Руководство по установке

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Page 67
Omni Installation Instructions
© Mass Electronics Pty Ltd 2017 Chapter 4 – Networking
4-4.3 RS-485 Wiring Topology
Installation of RS-485 connections on an Omni Network must adhere to the Bus topology. A Bus
Topology is produced by connecting from one device to the next and then onto the next.
A simple means to identify if bus topology is used is to check that:
• There are TWO end connections
• Any joining is made between TWO cable ends only
Furthermore, there are a number of rules which apply to the comms connection of a RS-485 Network:
• The screen must be continuous.
• Only one point earthed on the screen.
• Even if a network has a device with a soft earth, one hard earth is still required on that network.
• The Net and Global networks should have the same length cable run and path.
• If a repeater is installed, each side of that repeater is a separate network and each requires a
bonded earth connection on the screen.
• There are no End of Line termination (EOL) requirements on the RS-485 network.
Connection of devices via RS-485 is done by daisy chaining from one device to the next.
Innotech recommends connection of Omni controllers using Ethernet. If you proceed to connect Omni controllers
using this cable type, you will not be able to access the on-board web server, schedules and other advanced
functions.
IMPORTANT
COMMS
COMMS
COMMS
COMMS
COMMS
COMMS
COMMS
COMMS
U10 REMs are daisy
chained for connection
via the RS-485 Comms.
COMMS
COMMS
U10 REM final connection.
Remember to set the End Of
Line (EOL) jumper on the first
and last device on the RS-485
network.
C40
Place the jumper on
to set End of Line.
EOL Note:
In this example, the C40 and the
last REM require EOL jumpers
to be set.
COMMS
COMMS
COMMS
COMMS
Figure 4-13: Example U10 Wiring Topology - RS-485
4-4.3.1 Connecting the Omni U10 using RS-485
Connect one end of an appropriate RS-485 cable to a Comms terminal on the Omni Controller.
Connect the other end to the Comms terminal of a U10 REM. To connect subsequent U10 REMs,
connect one end of the RS-485 cable to the U10's Comms terminal and the other end to the next U10
REM. After connection, set the End of Line jumpers.