How to avoid disturbances on the bus when connecting a PCD8.K120 (Profi S-Link) cable

FAQ #100800

 

Problem
If the PCD8.K120 is connected to the bus, the bus is disturbed sometimes. The communication stops for a moment.

Origin
Due to the design of the Profibus connector all GND connections are on PIN 1 to 5 (all on the same side of the connector), on the other hand PIN 6 to 9 are the bus signals. If PIN 6 to 9 are connected first, the bus will be disturbed.

Solution
To avoid the disturbances on the bus please pay attention that PIN 1 to 5 are connected first (plug in the connector with a light tilt to one side so that the PIN 1 to PIN 5 side of the connector makes the first contact).