Scheduling

Data exchange in a LIN cluster is controlled or delegated by the LIN master. Using time points defined by a schedule (LIN schedule) the LIN master places a frame header on the bus, which a LIN slave then completes to form the LIN frame. In the case of a master request frame or a sporadic frame, the LIN master transmits the frame response itself.

Send times must be selected so that sufficient time is available to transmit the LIN frame. Provisions must be made for the time reserve of 40 % and possible jitter. The sum of the jitter and maximum transmission time to be scheduled, results in the minimum requirement in laying out a send or frame slot (target frame slot).

Because the LIN schedule or a frame slot is subdivided into mini-slots (e.g. 5 msec), and a mini-slot (corresponds to the time base defined in the LDF) represents the smallest time resolution for processing the LIN schedule, this usually results in a positive discrepancy between actual and target frame slots. That is because in transmitting a LIN frame, enough mini-slots must be provided to guarantee transmission of the relevant LIN frame. This positive discrepancy is referred to as the interframe space.