Both RS232 and RS485 data buses are connected to the XPORT serial input via a level converter to step the signal down to ... arduino clone + ethernet shield + max232 board off ebay. Report comment.

Linear Technology's LTC2872 is a multiprotocol 20-Mbit/s RS232 and 500-Kbit/s RS485 transceiver with switchable integrated termination for 3.3-V and 5-V systems.

It can read from my PLC directly via RS232 (through I will likely use RS485 with a protocol converter). I need to RPi to catch the data, dump it to a database of some sort that updates a HTML5 page.

“By incorporating RS485 connectivity, the Arduino Uno SPE Shield becomes a tool for upgrading RS485 legacy systems or integrating modern technologies with current infrastructures, creating a bridge ...

Robust Dual RS232/RS485 Multiprotocol Transceiver June 6, 2012 Linear Technology Corporation introduces the LTC2872 multiprotocol transceiver with switchable integrated termination for 3.3V and 5V ...