The ARTEMiS library contains the nodal interface blocks along with some other utility blocks used in the SSN algorithm.
The blocks above are SSN nodal interface blocks or NIB. They represent the nodes of the nodal method used in SSN. These SSN nodes connect state-space described groups that respect some causality laws.
For example, in a state-space approach, one cannot connect a current source in series with an inductance. SSN nodal interface blocks behave similarly. To achieve this, the block port has a type I (for current source) and V (for voltage source) and this type must be chosen to respect causality laws. Taking the 1-phase SSN nodal interface block as an example: the block has an I-type port and V-type port as selected on its dialog box below.