Secondary channel scanner timing

The SoftDevice will schedule a new secondary channel scanner timing-event if it receives a packet on a primary channel that points to a secondary channel or when it receives a secondary channel packet that points to another secondary packet. When the SoftDevice starts secondary channel scanning, it will pause all ongoing primary channel timing-events. It will resume primary channel scanning after it has completed all secondary channel timing-events.

Figure 1. Scanner timing - a secondary scan timing-event pauses primary channel scanning
Scanner timing - a secondary scan timing-event pauses primary channel scanning
Figure 2. Scanner timing - a secondary scan timing-event does not have to fit within the scanWindow
Scanner timing - a secondary scan timing-event does not have to fit within the scanWindow
Figure 3. Scanner timing - a secondary scan timing-event may occur between two primary channel timing-events
Scanner timing - a secondary scan timing-event may occur between two primary channel timing-events
Figure 4. Scanner timing - secondary scan timing-events will pause primary channel scanning
Scanner timing - secondary scan timing-events will pause primary channel scanning

Secondary channel timing-events may be interleaved by other timing activities. The advertiser decides when the secondary channel packets are sent. Therefore, the scanner cannot decide when the secondary scanning timing-events will occur.

Figure 5. Scanner timing - secondary scan timing-events will interleave with connections
Scanner timing - secondary scan timing-events will interleave with connections