it uses differential signalling over a pair of wires.It’s a sibling of the well-know RS-232 standard, with two main characteristics that set it apart: RS-485 is the common/short name for referring to the electrical standards for digital communication described in TIA-485 / EIA-485. the sniffer must support 24/7 operation, so it must be extremely reliable.data protocol (if any) is managed offline by parsing/post-processing the log files.captured data must be sent over Ethernet to a remote logging station.captured data must be timestamped with a 1 µs resolution.the sniffer must support sniffing raw UART data on an RS485 line running at a 1 Mbit/s bitrate over a twisted pair of wires, with standard UART settings (1 start bit, 8 data bits, no parity, 1 stop bit), and a dataflow of 1 message of 120 bytes every 20ms.it must be a passive spy/sniffer on the line. the monitoring must be transparent to the nodes, i.e.I had a need to monitor data exchanged between two nodes of an RS485 communication link, with the following requirements:
