A novel numerical analysis to characterize and to visualize the resonance behavior in a long cable is proposed. The resonance-due maximum amplification, and the frequency and position to which the maximum occurs, are represented in function of the load connected to the cable terminal in a 3-D plot here denominated "resonance surface response." This analysis is based on a white box modeling and allows the design of protective measures against the resonance phenomenon, such as filter design, protection against cross-talk, adequate voltage insulation choice, etc. One of these applications is exemplified: the design of an output filter for a power converter connected to a long cable, from which the results are compared to a classical design of the same filter to highlight the advantages and demonstrate the robustness of the proposed technique.Index Terms-Embedded system design, power cable, resonance in long cable, white-box model.