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Service Manual Combics
RS-232/RS-485 Option (A2/3) Pin Assignment
Slot for UNICOM RS-422/RS-485 Interface
The operating mode setting is carried out via switch SW1-4.
The PCB factory setting is RS-485 operation (option A3).
The switch must be reset to enable the card to operate via RS-422 (option A2).
The other switches are used to activate the transmission side.
Important!
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Switch settings must be made when replacing the PCB.
The following lists the configuration options:
Connection Function A2 (RS-422) Function A3 (RS-485)
1 TxD + TxD/RSD+
2 TxD - TxD/RSD-
3 RxD+ – –
4 RxD- – –
5 GND galvanic isolation GND galvanic isolation
6 GND galvanic isolation GND galvanic isolation
7 – – – –
8 – – – –
9 – – – –
10 – – – –
11 LINE_OUT* LINE_OUT *
12 LINE_OUT* LINE_OUT *
13 GND* GND*
14 GND* GND*
* no galvanic isolation
Interface Description | Unicom PCBs
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