The M12 connector provides RS-232 and RS-485 serial interfaces.
The 8-pin M12 connector is located on the side of the air quality transmitter and provides power and data to the transmitter.
The following pinout is from the side of AQT530, not the cable.
| M12 pin | Wire color | RS-232 | RS-485 |
|---|---|---|---|
| 1 | White | Data GND | Data GND |
| 2 | Brown | RX (input) | − |
| 3 | Green | TX (output) | − |
| 4 | Yellow | No connection (floating) | |
| 5 | Gray | − | B (-) |
| 6 | Pink | − | A (+) |
| 7 | Blue | Power GND | Power GND |
| 8 | Red | Power 10 ... 25 V DC | Power 10 ... 25 V DC |
| − | Black | Cable GND | Cable GND |
RS-232 serial interface
The RS-232 interface is used mainly for the maintenance connection.
RS-485 serial interface
The RS-485 interface is used mainly for the data connection.
RS-485 supports Modbus ASCII and Modbus RTU, and ASCII formatted text with comma separated values (CSV).