RS485 Networking with MINI-MAX

RS485 is a standard for electronic data transmission, especially over long distances ( up to 4000 feet ), high data rates ( several megabits/second ) and/or electrically noisy environments. RS485 uses a differential data transmission which makes it immune to common mode noise. RS485 also allows a multi-drop configuration where multiple transceivers (nodes) can receive and transmit on the same pair of wires.

MINI-MAX boards can be connected to an RS485 transceiver to communicate with each other or with other devices on an RS485 network. These boards have a built-in RS232 converter with Receive (RXD), Transmit(TXD) and RTS (Ready-To-Send) pins. RTS can be activated under software control when the board is ready to transmit on the RS485 bus. Most MINI-MAX boards also have an option ( jumper ) to provide 5V power on the RS232 connector. This can be used to power and external RS232/RS485 converter.

Here is a diagram of RS232 to Rs485 conversion: