srne-mqtt/Connector.md

Connector

The connector is a RJ12 (6P6C, phone connector with all 6 positions populated) The interface uses RS-232 levels (±15V)

Pinout

Seen from the end of the RJ12 plug

    ┌───┐
┌───┘   └───┐
│           │
├─┬─┬─┬─┬─┬─┤
│1│2│3│4│5│6│
└─┴─┴─┴─┴─┴─┘

1. TX
2. RX
3. GND
4. GND
5. +V
6. +V

+V seems to be a regulated 14.6V supply, current limited by a 100Ω resistor RX and TX has 100Ω resistors in series.