Method for passing a token in a local-area network

Abstract

The method by which the right of access to the common communication medium of an initialized local-area network is transferred between modules having access to the medium by the module having such access transmitting a token to a designated existing and properly functioning module. Each such module is assigned a unique address, its MY ADDRESS, and has the data-processing capabilities to determine and store the address of the module to which it last successfully transferred a token, its LAST SUCCESS ADDRESS. Each module also determines the address of a module, if any, between its LAST SUCCESS ADDRESS and its MY ADDRESS, its TRY ADDRESS. The module which has accepted a token will try to pass a token to the module whose address is that of its TRY ADDRESS if its TRY ADDRESS differs from its LAST SUCCESS ADDRESS before attempting to pass a token to the module whose address is that of its LAST SUCCESS ADDRESS. Each module calculates a different TRY ADDRESS if the difference between its MY ADDRESS and its LAST SUCCESS ADDRESS is greater than one each time it successfully passes a token to another module.