Mettler Toledo IND231 Manuel D'installation page 33

2.4.8. Wiring Connections for Options
Options for the IND231/IND236 that require external connections include the following:
•
•
•
2.4.8.1. COM2 with Isolated RS-232/422/485 Option
The COM2 with RS-232/422/485 option board (Figure 2-35) provides a single isolated serial port.
The COM2 port provides RS-232, RS-422and RS-485 connections. The hardware connection must
be configured in the Communication section of the setup menu structure – refer to Chapter 3,
Configuration. Figure 2-37 and Table 2-6 show the connection details.
The jumpers on the board (W1 and W2, indicated in Figure 2-35) are open by default. They enable
the connection of a 120 ohm terminal resistor to the RS-422 and RS-485 A/B signals. If it is
necessary to enable the terminal resistor, short the jumpers as shown in Figure 2-36.
30094756 | 04 | 02/2021
COM2 with isolated RS-232/422/485
USB Interface
Discrete I/O interface
Connector to
Main board
Connector for
RS-422 and
RS-485
Figure 2-35: COM2 with RS-232/422/485
Figure 2-36: COM2 Jumper Positions
NOTES:
1. RS-232: MAXIMUM CABLE LENGTH: 50 FEET (15
METERS)
2. RS-422/485: MAXIMUM CABLE LENGTH: 1000 FEET
(304 METERS)
3. WIRE SIZE: 18 AWG (0.832 mm
Figure 2-37: COM2 Port Signals
METTLER TOLEDO IND231/IND236 Installation Manual
Jumpers for RS-
422/485 terminal
resistor
RS-232 Connector
2 ) MAXIMUM
24 AWG (0.205 mm ) MINIMUM
2
2-19