SDD4P in ADS port voltages and currents

Hello all,

Could someone please help me with using SDD4P in ADS. How to define the port voltages and currents etc.
Thanks

_v1, _v2, _v3, _v4, _i1, _i2, _i3, _i4
Surely read documents.
http://edadocs.software.keysight.com...efined+Devices