A test rig for testing a power transmission device, having an input shaft, an output shaft and a casing, may include a first assembly having a coupling shaft that is connected by a rigid and coaxial coupler to the output shaft of the power transmission device. The capacitor structures include a bottom electrode, a top electrode and a dielectric layer interposed between the bottom electrode and the top electrode. When the line connection state is a broadband connection, the data is read directly from and written directly into a data storing device of the server. The second layer is a combined Hypertext Transport Protocol server and Simple Network Management Protocol manager. The antenna device comprises a first grounded conductor, an antenna element mounted on the first grounded conductor via an insulator, a second grounded conductor disposed separate from the first grounded conductor, and a changing unit for changing directivity of the antenna element by adding the second grounded conductor to the first grounded conductor or canceling the addition thereof.