<model> <name>d_source</name> <type>Digital</type> <node_number>1</node_number> <title>Add Parameters for Digital Source</title> <split>4-V</split> <param> <input_file default ="source.txt">Enter Input File (default=source.txt)</input_file> <input_load default ="1.0e-12">Enter Input Load</input_load> </param> </model>