Innotech Genesis II Digital Controller (v5) - Manual (Page 115)

Page 115
Genesis II Installation Instructions
© Mass Electronics Pty Ltd 2010 Chapter 5 – Network Installation
Neither the Innotech Repeater IR11 or IR12 have a separate earth terminal as it is a 24VAC powered
device; however, the 24 V supply must be earthed on the 0 V side for safety and to make use of the
Soft Earth feature.
The IR12 is the current dual channel and dual baud rate repeater. The IR11 is the current single
channel dual baud rate repeater. The IR12 and IR11 are fully isolated and both Port 1 and Port 2
offer the same level of protection. That means that both Ports 1 & 2 can be used for the remote site
connection.
Building A Building B
Hard Earth
Port 1 Port 2
Soft Earth
Hard Earth
5-3.5.5 GENII MPI Modem Printer Interface
The GENII MPI Modem and Printer Interface can be used with both the Genesis II Direct Digital
Controller and MPCII Mid Points Controller.
The MPI is supplied with a double insulated plug pack, which isolates the MPI power supply from the
electrical earth. However, when a printer or PC is connected to the MPI it will be connected to the
electrical earth via the printer and/or PC cables. See Figure 5-14 .
The Comms is connected to the MPI via the RJ11 socket on the rear of the MPI. The top portion
of Figure 5-14 shows the socket connections and the cable as supplied. The standard order for
conductor colours is shown, but they may change and, therefore, should always be checked before
connecting.
To isolate the screen of the Comms cabling from electrical earth at a non-isolated MPI, do not
connect the two GND conductors of the flat MPI cable to the screen(s) of the Comms cables at the
wall connection. This is not an isolated connection for the data conductors.
To provide isolation for the data conductors, an MPI fitted with RS485 isolation ICs must be used.
The two GND conductors should be connected to the screen(s) of the Comms cable when an isolated
MPI is used. Connecting the screen(s) of the Comms cable(s) completes the internal overvoltage
protection on the MPI data connections.
The earth on the Innotech Repeater IR12 must be connected to the soft earth terminal.
NOTE
Refer to Figure 5-13 below for a common networking example, using the Innotech Repeater IR12
Module.
Figure 5-13: Networking and Earthing the Innotech Repeater IR12