Recently, the first section of a superconducting (SC) continuous wave (CW) linac has been extensively tested with heavy ion beam from the GSI High Charge State Injector (HLI). During this testing phase, the reliable operability of 217 MHz multi-gap crossbar-H-mode (CH) cavities has been successfully demonstrated. The SC 217 MHz CH cavity (CH-0) of the demonstrator setup accelerated heavy ions up to the design beam energy and even beyond at high beam intensities and full transmission. This worldwide first beam test with a SC CH cavity is a major milestone on the way realizing the entire SC CW linac project. In this contribution further RF measurements on the cavity are presented providing full characterization of the RF structure CH-0.