IQH3A IQ 3U Modular Enclosure
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Installation
Issue 2 Rev 2
Page 31
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2014 Snell Limited
Gateways ship with a default setting of RS-232.
3.15.1.2
RollNet 75 Ohm Coaxial Interface
This interface allows connections of units to a single section of 75 Ohm video cable. Each unit
is physically joined via a T or Y-piece connector. Each end of the section is terminated by a 75
Ohm resistor at each end of the cable. The data rate on this interface is 2.5 Mbps. Each
section of cable can be up to 400 m.
Example configuration:
3.15.1.3
RollNet RS-485 Differential Interface
Sections of the coaxial network can be joined using the RS-485 bus. The RS-485 connections
are limited to shorter distances but are multi-drop allowing a rich combination of network
configurations. The combined total number of units across the coaxial network and the
RS-485 bus is still 255 nodes and the total network length can be up to 1500m.
The maximum number of hub transitions between any number of nodes on a single local area
network is 4.
Mode
SW1 1-7
SW1 8
SW7 1-4
RS-232
OPEN
-----
CLOSED
RS-422
CLOSED
CLOSED
OPEN
RS-485
CLOSED
OPEN
OPEN
