Device in a system operating with CAN-protocol and in a control and/or supervision system

A system for radio-controlling machines operating with the Controller Area Network (CAN) protocol, the system comprising:

• a number of machines that each have a radio communication means for communicating with another of said radio communication means, each machine having a number of modules interconnected by a digital serial connection that communicate with one another using the CAN system protocol;
• a key allocation means for determining which of said machines may communicate through a particular instance of a message channel established between a subset of said machines and a master control system or between a subset of said machines alone, said key allocation means dynamically assigning each of said machines, within the subset of machines assigned to a message channel, a unique identification during each instance of an established message channel;
• wherein:
• said master control system includes said key allocation means and each of said modules either includes said key allocation means or is capable of adopting an assigned identification from said key allocation means,
• said identification is based not upon the real identity of said machine, but is dynamically assigned during a communicative coupling between said master control system and said module within said machine or between a plurality of modules in separate machines, and
• said modules in any particular machine have unique identities and the unique identity of a particular module, or the unique identities of multiple modules in the machine form(s) the identity/identities for said particular machine's radio communication means.