IQH1S 1U Enclosure
SECTION 3
IQH1SOPS
23/11/06
www.snellwilcox.com
Version 1 Issue 4
3.7
RollNet RS485 Differential Interface
Sections of the coaxial network can be joined using the RS485 bus. The RS485 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 RS485 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 is 6.
OK
Not OK
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-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 Mb/s. Each section of cable can be up to 400m.
Example configuration:
3U Box
3U Box
1U Box
75 Ohm Network
Front Panel
75 Ohm
Terminator
75 Ohm
Terminator
