This test case is a shielded twisted pair atteuation calculation, The cable specification is based on a SpaceWire shielded twisted pair. We have used this test case to look at the convergence of results with respect to parameters which control the representation of cylindrical conductors and segment decomposition in FastHenry. The script run_parameter_set generates and runs a SACAMOS Spice cable bundle model for each of the sets of parameters specified in the parameter_list.dat file. These parameters are as follows: NLAYER: Number of rectangular layers to divide the cylindrical geometry into (number of layers in one radius) NWINC: FastHenry filament decomposition parameter, nwinc NHINC: FastHenry filament decomposition parameter, nhinc NSAMPLES: Number of frequency samples in the FastHenry calculation FMAX: maximum frequency in the FastHenry calculation This process can be used to test the convergence of results with respect to these parameters. The results in STP_DM_NLAYER_RESULTS show convergence with respect to the NLAYER parameter.