Potential Ratios - Siemens SIMATIC PN/J1939 LINK Operating Instructions Manual

7.2

Potential ratios

Electrical isolation
Electrical isolation is provided between the following switching components with the
PN/J1939 LINK:
● The signals of the PROFINET interfaces are electrically isolated from each other, from
the electronics or 24 V supply voltage and from the fieldbus interfaces.
● The J1939/CAN interface is electrically isolated from the power supply.
Shielding
The shields of the PROFINET interface are galvanically connected.
NOTICE
Sufficient interference immunity is only achieved through EMC compliant application of the
cable shields of the PROFINET cables to a shield rail.
The shields of the J1939/CAN interface are capacitively decoupled from the shields of the
PROFINET interface to prevent compensating currents over the cable shields.
Figure 7-1
SIMATIC PN/J1939 LINK
Operating Instructions, 12/2018, A5E45307564-AA
Block diagram shielding
Connecting
7.2 Potential ratios
37