Emerson Rosemount 3410 Series Installation Manual page 53

Installation manual
00825-0600-3104
BLACK wire goes to COM (see
Port A, uses TX+ and TX- on the CPU Module and has a ground wire.
When Belden wire No. 9940 or equivalent is used, the maximum cable length for RS-232
communications at 9600 bps is 88.3 meters (250 ft.) and the maximum cable length for
RS-485 communication at 57600 bps is 600 meters (1970 ft.).
Port A supports a special override mode which forces the port to use known
communication values (19200 baud, address 32, RS-232). Note that the protocol is auto-
detected. This mode is expected to be used during meter commissioning (to establish
initial communication) and in the event that the user cannot communicate with the meter
(possibly due to an inadvertent communication configuration change). Alternately, when
using MeterLink
to connect the PC.
Each serial port can be independently configured as read only in meter serial connection
settings. Read only serial ports prevent write access, program downloads, alarm
acknowledgements and testing of outputs. The read only serial port setting is configurable
through Edit → Compare Page by modifying configuration point ReadWriteModePortA, B
or C, and changing to Read-only mode.
Table 3-4: Serial Port A parameters
Port/
Communication
Port A (Standard)
• RS-232
• RS-485 Half
Duplex
• RS-485 Full
Duplex
• RS-485
wire
communication
on Port A)
(1) RS-485 2-wire connections use TX+ and TX - on the CPU Module.
(2) Denotes auto-detected protocols.
Installation manual
Figure 3-9
with an Ethernet port, use Ethernet cable, Rosemount P/N 1-360-01-596,
™
Description
• Typically used for general
communications with a flow
computer, RTU (Modbus slave)
and radios.
• RS-485 - 2-wire (Half Duplex)
connected to TX+ and TX-
• Special override mode to force
(1) (2-
port configuration to known
settings.
• Supports RTS/CTS handshaking
with software- configurable RTS
on/off delay times.
• Factory default is RS-232,
Address32, 19200 baud
for Port A wiring). RS-485, 2-wire connection on
Common features
• Communications via MeterLink
using RS-232 or RS-485 Full Duplex
• Software configurable Modbus
Address (1-247)
• Auto-detects TCP/IP and ASCII or
RTU Protocol
— ASCII Protocol:
•
— Parity: odd or even 1, Stop Bits
= 1
— Baud Rates: 1200, 2400, 9600,
19200, 38400, 57600, 115000
bps
— RTU Protocol:
•
— Parity: odd or even 1, Stop Bits
= 1
— Baud Rates: 1200, 2400, 9600,
19200, 38400, 57600, 115000
bps
• Each port is software configurable
as Read-only.
Electrical installation
October 2023
Start Bits = 1, Data Bits =
7 (2)
(2)
Start Bits = 1, Data Bits =
8 (2)
(2)
53