Specifications

DRAGON™
6
2
The two RS485 connectors are identical in every respect so that the point-to-point
cables can be chained together without limitations concerning the bus wiring.
Obviously cable length is to be kept to a minimum as with all bus systems.
2.6.2 Network Cabling
The Multidrop line is made using RJ45 connectors and a cable having the following
specifications:
• twisted pair AWG 24 wires
• 120 Ω impedance
• maximum network cable length 1200 meters
Pin Function Multidrop Cables
1 RS485 +
2 RS485 -
3 N.C.
4 VDC –
5 VDC –
6 N.C.
7 VDC +
8 VDC +
5
2
RJ45
5
2
RJ45
1 1
V
DC-
RS485-
RS485+
Twisted Pair - RS485 bus
8
5
2
RJ45
8
5
2
RJ45
1 1
Twisted Pair - RS485 bus
Twisted Pair - Power su
pp
l
y
VDC+
V
DC-
RS485
RS485
When wiring the multidrop cables, note the following:
Pin 8 (or 7) can be connected only if the power has to be propagated from a cradle to a
STARGATE™ base station or STAR-Box™ converter via the cable.
Pins 5 (or 4) should always be connected as reference ground.
To avoid excessive voltage drop, it is recommended to not propagate power between
OM-DRAGON™ cradles when used as battery chargers but to supply each cradle
Data
only
Data
and
Power
Supply
Pin 1