Note
Unless dual Ethernet ports were specified at the time of order, the secondary Ethernet port
(Ethernet 2) will not be active.
3.4.3
RS-485
The Gateway may be ordered with an optional RS-485 (serial) connection (
referenced by the A and B Serial Modbus terminals. This connection is used to
communicate Modbus RTU on an RS-485 data bus.
Use 18 AWG single twisted shielded pair wiring to connect the Gateway to the RS-485 data
bus. The total bus length should not exceed 4000 ft. (1220 m). Connect the Tx + (positive,
transmit) wire to terminal A and the Rx - (negative, receive) wire to terminal B. The wiring
shield should be trimmed close and insulated from touching the Gateway enclosure or
other terminations. Only terminated at one end typically at the power supply end.
If the existing data bus uses a 4 wire Full Duplex configuration, see
a 2-wire Half Duplex configuration.
Figure 3-8: Convert from Full to Half Duplex
Tx
Rx
Tx
Rx
(A)
(B)
Reference Manual
Installation
00809-0200-4420
September 2020
Emerson.com/Rosemount
25
Summary of Contents for Smart Wireless Gateway 1420
Page 1: ...Reference Manual 00809 0200 4420 Rev HE September 2020 Emerson Wireless 1420 Gateway ...
Page 34: ...Installation Reference Manual September 2020 00809 0200 4420 34 Emerson com Rosemount ...
Page 42: ...Commissioning Reference Manual September 2020 00809 0200 4420 42 Emerson com Rosemount ...
Page 62: ...Troubleshooting Reference Manual September 2020 00809 0200 4420 62 Emerson com Rosemount ...
Page 84: ...DeltaV Ready Reference Manual September 2020 00809 0200 4420 84 Emerson com Rosemount ...
Page 95: ...Reference Manual 00809 0200 4420 September 2020 Emerson com Rosemount 95 ...