Emerson Rosemount 5400 Series Reference Manual page 76

Section 4: Electrical Installation
November 2014
Alternatively, the Rosemount 5400 Series Transmitter can be installed as shown in
If this wiring layout is used, there is an increased risk for communication disturbances due to
differences in potential between grounding points. By using the same grounding point for
Modbus Master and Power Supply, this risk is reduced.
Figure 4-18. Alternative Multidrop Connection of Rosemount 5400 Series Transmitters
120 :
RS-485 bus
Internal
ground screw
Star topology
For a star topology connection of the Rosemount 5400 Series transmitters, the transmitter with
the longest cable run needs to be fitted with a 120 : termination resistor.
Figure 4-19. Star Topology Connection of Rosemount 5400 Series Transmitters
64
HART to Modbus Converter
MB
MA
MODBUS
(RS-485)
POWER
HART
Ambients > 60 ºC
Use wiring rated
for min 90 ºC
External
ground screw
HART to Modbus Converter
MB
MA
MODBUS
(RS-485)
POWER
HART Ambients > 60 ºC
Use wiring rated
for min 90 ºC
HART to Modbus Converter
MB
MA
MODBUS
(RS-485)
POWER
Ambients > 60 ºC
HART Use wiring rated
for min 90 ºC
HART to Modbus Converter
MB
MODBUS MA
(RS-485)
POWER
Ambients > 60 ºC
HART Use wiring rated
for min 90 ºC
HART to Modbus Converter
MB
MA
MODBUS
(RS-485)
POWER
HART
Ambients > 60 ºC
Use wiring rated
for min 90 ºC
Internal
ground screw
External
ground screw
HART to Modbus Converter
MB
MA
MODBUS
(RS-485)
POWER
HART Ambients > 60 ºC
Use wiring rated
for min 90 ºC
Reference Manual
00809-0100-4026, Rev HA
120 W
Power
supply
For a star topology
connection, connect
the 120 :
verter
termination resistor
MB
MA
MODBUS
to the transmitter
(RS-485)
HART to Modbus Converter
MB
MA
MODBUS
(RS-485)
POWER with the longest
HART Ambients > 60 ºC
Use wiring rated
for min 90 ºC
cable run.
Electrical Installation
Figure 4-18.
B Modbus
A master
Z