BECKHOFF BC3150 - Manual (Page 23)

Safety Instructions
Fieldbus Components 21
PROFIBUS Connection
M12 circular connector
The M12 socket is inverse coded, and has five pins. Pin 1 is 5 V
DC
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 Profibus 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
Nine pole D-Sub
Pin 6 is 5 V
DC
und Pin 5 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 3 and pin 8 are the Profibus signals. These must never be swapped
over, as this will prevent communication. Shield is connected to the D-Sub housing that is coupled with low-
resistance to the mounting rail.
D-Sub socket pin assignment
Profibus conductor colors
Profibus conductors M12 D-Sub
B red Pin 4 Pin 3
A green Pin 2 Pin 8