Kevin, I used the same shunt as the Victron BMV712.  The shunt creates a voltage potential difference across it as current changes. Multiple devices can read this potential difference without significant change in the resulting measurement.  You need about 40-50 feet of  four strand, 16 gauge wire to get from the back of the engine room up behind the helm station and instruments and they the conduit into the passagway and then back down to the battery box for the wires that provide the WS with voltage and current.  The voltage needs to come directly from the batteries not from the alternator. I am getting both the current and then battery voltage at the shunt.   The WS 500 comes with good supporting documentation.  It's worth making sure you read through it all.