A cylinder crankcase for an internal combustion engine, the base body 1 of the engine consisting of a material A and the cylinder walls 2 of the engine of a second material B, and a lattice-like reinforcement 3 provided between the two materials A, B. A bumper disposed to contact the contact arm when the contact arm is in the blown open position. In this way, the frame data in the VC4 frame format is emulated, a requirement of transparently transmitting AU pointers in the present network is fulfilled, that is, the requirement of emulating and transparently transmitting the content of an entire AU is fulfilled. If data becomes corrupted, the data blocks of the preservation memory are applied to the corrupted data in reverse chronological order until such time that a valid, non-corrupted set of data is obtained. Each second period is time required for the second comparison voltage to change from the second reference voltage to the same voltage as the second signal voltage.