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Electrical Installation
November 2017
Figure 4-5. Wiring the 4-20mA to Emerson
A. Rosemount 5708 housing ground shield
B. THUM Adapter
C. Green
D. Yellow
E. White
F. Black
G. Red
4.5.2
RS-485 communication
The unit includes an RS-485 communication port. This type of connection allows a PLC/DCS/laptop to
communicate with the Rosemount 5708. It also allows a connection of multiple Rosemount 5708 in a
system on the same RS-485 bus and communication with all devices using a single connection to the
computer running the software.
It is required to use an appropriate cable rated for RS-485, the cable should be of twisted pair, have
120 Ω impedance and shielded. The total length of the cable should not reach 3280 ft (1000 m).
If multiple units of Rosemount 5708 is connected together, all devices must be connected in parallel
mode in the RS-485 ports. Hence, all the '+' (positive) ports of the RS-485 should commonly be
connected and all the '-' (negative) ports of the RS-485 should be connected commonly. The connection
must be of Daisy-Chain type and have at each of the far ends of the chain 120 Ω resistor (such resistor is
provided with the Rosemount 5708), as shown in
The communication cable must be grounded at one side. This ground needs to be the same grounding
as the power supply ground.
Each Rosemount 5708 must be configured with a different polling address.
30
A
250 Ω
B
C
D
E
F
G
™
Wireless THUM
24DC
Figure
4-6.
Reference Manual
00809-0100-4570, Rev DA
™
Adapter
Electrical Installation
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