Hi Wouter, yes the INDIO unit comes with a RS485 port. You probably know the difference between RS485 and RS422:
our half-duplex RS485 is sending/receiving on the same (twisted) pair cable (A,B) with a pin to select the direction
RS422 is full duplex, with 2 (twisted) pairs: one sending, one receiving.
So, if you want the INDIO to receive RS422 data, you can just fix the RS485 direction pin to 'receive' and connect your RS422 sending pair (TXD-, TXD+) to the RS485 terminals (A,B).
The INDIO's RS485 is connected to the serial UART 'Serial' so you can use standard Arduino parsing commands.
For sending out data over RS232 we'd suggest to add a GSM/GPRS module which has an RS232 port and you can configure that to connect to the second hardware serial 'Serial1'. This would be the most robust solution, but you could also add your own UART TTL to RS232 converter on the 14-pin IDC connector.
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