QUEUED ACCESS OF COMMON COMMUNICATIONS LINK WITH EXPANDED ADDRESSING AND ERROR CHECKING PROTOCOL

摘要

QUEUED ACCESS OF COMMON COMMUNICATIONS LINK WITH EXPANDED ADDRESSING AND ERROR CHECKING PROTOCOL An arrangement for providing a multi-level access bus protocol utilizing a dynamically established bus access timing relationship for a plurality of devices competing for the use of a common data line. Bus access timing changes with the occurrence of successes and failures in attempts to access the data line to provide a deterministic communication scheme in a bus topology. Further aspects of the invention include the use of a modified checksum to avoid the transmission of homogeneous (all same binary value bits) data packets on the data line; means for dynamically establishing the end of a variable length data packet, an addressing scheme permitting universal and family addressing of all devices on the data line; and a means for providing message-type prioritization.