SYSPHS12 — The resistance:ViscousResistance in Figure 60 has to be treated as a PhSVariable not a PhSConstant or the systems of equations is ill formed

In Figure 60: Hydraulics blocks, ports, & component properties

The resistance:ViscousResistance has to be treated as a PhSVariable not a PhSConstant or the system of equations for ConnectedTanks is ill formed. Validation of the export in one Modelica tool gives:

    The model has 6 variables and 7 equations.

Even though resistance:ViscousResistance is effectively a constant (as it is always computed from values that don't change with time) it is in fact handled like a variable via a Constraint:

{resistance=(8*viscosity*length)/(3.1416*(radius^4))}