Mettler Toledo IND131 Installationshandbuch Seite 50

IND131/IND331 Terminals Installation Manual
COM2 Connections
The COM2 serial port is part of the COM2/Discrete I/O option board. There are two
versions of this board depending upon the version of discrete output devices. Both
versions support the same COM2 functions. The COM2/Discrete I/O (Relay) option
board is shown in Figure 2-41 and the COM2/Discrete I/O (Solid State) option
board is shown in Figure 2-46. The COM2 port is positioned to the far left side of
the board.
The COM2 port includes connections for RS-232 and RS-485. Table 2-8 indicates
which terminal is which signal on the COM2 port. The type of interface used must
be selected in the setup of COM2.
For an example of connecting an external RS-232 device to the COM2 serial port,
refer to Figure 2-37, as RS-232 connections are similar for COM1 and COM2. An
example of connecting an RS-485 device is shown in Figure 2-40.
2-26
Table 2-8: COM2 Connections
Terminal
TxD Transmit RS-232
RxD Receive RS-232
Gnd Logic Ground
Tx+ A Transmit + RS-485
Tx- B Transmit - RS-485
NOTES:
1. USE ONLY SHIELDED CABLE.
2. MAXIMUM CABLE LENGTH: 1000 FEET (304 METERS).
3. WIRE SIZE: 18 AWG (0.8 mm
24 AWG (0.2 mm
Figure 2-40: Wiring to COM2
Signal
2
) MAXIMUM
2
) MINIMUM.