PROFIBUS wiring error / B-line short
PROFIBUS wiring error / B-line short IDX attended a PROFIBUS call out for a gold mine situated in Welkom. The client reported issues as “loss of communication and network trips”. Using the PROCENTEC Mercury Pro Kit (A complete diagnostics tool for troubleshooting PROFIBUS and Industrial Ethernet Networks) we were able to identify the underlying issue as a short between the B-core (red wire) and the PROFIBUS cable shield. The short in the PROFIBUS cable meant that the differential signal was significantly lower in amplitude and therefore more susceptible to earthing faults and EMI injections on the bus. PROFIBUS makes use of a balanced signal. This means that the signal transmitted on the A and B channels have similar voltage levels, however, they have opposite polarities. The differential signal is calculated as B – ( – A). When a short occurs on the PROFIBUS cable between either of these cores and the PROFIBUS cable shield, the shorted core w...




