Emerson 5301HxxxxxxxxxxxxxxZZ Series Reference Manual page 100

Electrical installation
April 2019
Table 4-3: Connection Terminals
Connector label
MA
MB
POWER +
POWER -
(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
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
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.
100
(continued)
Description
Modbus RS-485 B connection
(RX/TX+)
Modbus RS-485 A connection
(1)
(RX/TX-)
Positive power input terminal
Negative power input terminal
HART to Modbus Converter
MB
MA
MODBUS
(RS-485) -
-
+
POWER
HART Ambients > 60 ºC
Use wiring rated
+
for min 90 ºC
identifies multidrop wiring topology, where up to 32 devices may be wired
Comment
Connect to RTU
(1)
Apply +8 Vdc to +30 Vdc (max.
rating)
Rosemount 5300 Level Transmitter
Reference Manual
00809-0100-4530