A shredder or mixer apparatus for the shredding or mixing of bulk material and which is mounted on a mobile chassis which may be driven by a power source on the chassis or pulled by a tractor or truck therefor. The second computer determines whether the heartbeat message is received, the receipt of which heartbeat message is indicative that the network is connected to the Internet. The attachment element can be attached to the gear mechanism housing by an end region and has an expansion plug part which projects through a recess in the fitting part, and has a passage opening axial to the recess in the fitting part and an identical cross section. Further, each support arch can be connected to at least one of the other support arches.