Mettler Toledo ACM500 Installationsanleitung Seite 34

COM3 provides RS-232, RS-422 or RS-485 connections. The COM3 signal names are shown in
Table 3-6.
Some examples of connecting external equipment to COM3 are shown in Figure 3-18.
64061976 | 07 | 01/2019
Table 3-6: COM3 Signal Names
Terminal Signal
TxD Transmit RS-232
RxD Receive RS-232
Gnd Logic Ground
TxD3+ +Transmit RS-422, RS-485
TxD3- -Transmit RS-422, RS-485
RxD3+ +Receive RS-422, RS-485
RxD3- -Receive RS-422, RS-485
Figure 3-18: Wiring to COM3
METTLER TOLEDO ACM500 Installation Manual
Notes
Jumper to RxD3+ for RS-485
Jumper to RxD3- for RS-485
Jumper to TxD3+ for RS-485
Jumper to TxD3- for RS-485
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