Communication bus system with mitigation of slave station locking problem and master station for use in such communication bus system

A multistation communication bus system including a plurality of master stations for addressing a slave station by winning an arbitration, one of said master stations comprising:

• a first master station including:
• frame-based arbitration means for attempting to address said slave station;
• arbitration outcome detection means for detecting whether said slave station is addressed;
• frame formatting means for, upon winning said arbitration, transmitting a frame-wise organized message including locking and unlocking signals for locking and unlocking, respectively, said addressed slave station for a duration of multiple frames contained in said message so that another of said master stations is blocked from, at least in a predetermined manner, accessing a locked station during said duration;
• and
• a second master station including:
• sequencing means, for upon detecting being blocked, executing a first sequence of retry undertakings at a combined time length that is substantially less than a standard maximum value of said duration followed by a second sequence of retry undertakings, said undertakings in said second sequence having a lower frequency than said undertakings in said first sequence, at a combined time length more than a standard maximum value of said duration.