One is total condensation. In this case the vapor quality output is made equal to 0, and the maximum condensable flow is calculated. You must supply the pressure at both ends of the pipe. This model reflects the situation of heating tubes provided with steam traps.
The second option is partial condensation. In this case you can specify both ends pressures, or one pressue and the flow. A check is done in order to assure that total condensation doesn't occurs.