Emerson Rosemount 5300 Series - Page 100

Table 4-3: Connection Terminals (continued)
Connector label Description Comment
MA Modbus RS-485 B connection
(RX/TX+)
(1)
Connect to RTU
MB Modbus RS-485 A connection
(RX/TX-)
(1)
POWER + Positive power input terminal Apply +8 Vdc to +30 Vdc (max.
rating)
POWER - Negative power input terminal
(1) The designation of the connectors do not follow the EIA-485 standard, which states that RX/TX-
should be referred to as 'A' and RX/TX+ as 'B'.
Figure 4-8: Connection Terminals for Rosemount 5300 with HART to Modbus
Converter
MODBUS
POWER
HART
(RS-485)
HART to Modbus Converter
MB
MA
Ambients > 60 ºC
Use wiring rated
for min 90 ºC
-
-
+
+
$
%
A. HART -
B. HART +
4.7.7
RS-485 bus
• The Rosemount 5300 Level Transmitter does not provide electrical isolation between
the RS-485 bus and the transmitter power supply.
• Maintain a bus topology and minimize stub length.
• Figure 4-10 identifies multidrop wiring topology, where up to 32 devices may be wired
on one RS-485 bus.
• The RS-485 bus needs to be terminated once at each end, but should not be
terminated elsewhere on the bus.
Electrical installation Reference Manual
April 2019 00809-0100-4530
100 Rosemount 5300 Level Transmitter