Hi @mohamed-dounnani,
the addressing is as follows:
/dev/extcomm/0/... <- All serial ports (0 = RS485 1.1, 1 = RS485 2.1)
/dev/extcomm/1/... <- Serial ports of Group 1 (0 = RS485 1.1)
/dev/extcomm/2/... <- Serial ports of Group 2 (0 = RS485 2.1)
You can reveal the structure by listing the directory:
unipi@L503-sn101:~ $ ls -l /dev/extcomm/* /dev/extcomm/0: total 0 lrwxrwxrwx 1 root root 12 Aug 31 09:51 0 -> ../../ttyNS0 lrwxrwxrwx 1 root root 12 Aug 31 09:51 1 -> ../../ttyNS1 /dev/extcomm/1: total 0 lrwxrwxrwx 1 root root 12 Aug 31 09:51 0 -> ../../ttyNS0 /dev/extcomm/2: total 0 lrwxrwxrwx 1 root root 12 Aug 31 09:51 0 -> ../../ttyNS1Martin