Modbus RS485 connection
M12 circular connector
The M12 socket is inverse coded, and has five pins. Pin 1 is 5 VDC and 3 is GND for the active termination resistor. These must never be misused for other functions, as this can lead to destruction of the device. Pin 2 and pin 4 are the Modbus signals. These must never be swapped over, as this will prevent communication. Pin 5 is the shield, and this is capacitatively coupled to the Fieldbus Box chassis.
M12 socket pin assignment
|
Type |
M12 |
9 pin D-Sub |
|---|---|---|
|
+5 V DC |
Pin 1 |
Pin 6 |
|
TxD/RxD |
Pin 2 |
Pin 3 |
|
GND |
Pin 3 |
Pin 5 |
|
RxD/TxD |
Pin 4 |
Pin 8 |
|
Shield |
Pin 5 |
D-Sub female connector (case) |