DP2P Response Handshake consists of 3 special DP2P packets described below. Every [N] addressed by the SelectedNodes field of the DP2P Request has a dedicated timeslot for DP2P Response Handshake after it receives DP2P Request. The index of the timeslot equals the index of the bit corresponding to the [N] in the SelectedNodes field. If [N] does not receive the DP2P Request then its timeslot remains empty i.e. unutilized. All following packets are sent using _TX_STD without _STDL mode.
Note: in the pictures below we interchange the term Timeslot for the term DP2P Response Handshake as it is shorter to write.
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Timeslot #0 |
Timeslot #1 |
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Last timeslot |
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DP2P Request |
1st selected [N] |
2nd selected [N] |
… |
The last selected [N] |
For instance, if only two [Ns] #2 and #11 from the above example are selected, then [N] #2 uses the 1st timeslot while [N] #11 has the 2nd (last) one.
At the beginning of the timeslot i.e. DP2P Response Handshake, the [N] first sends DP2P Invite, then waits for the DP2P Confirm, and finally sends DP2P Response. Invite and Confirm packets are used to protect the communication against resending previously sniffed DP2P Request packets. Please see the details below and DP2Papp.c and DP2Papp-UART.c examples for the implementation.
DP2P Response Handshake detail:
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Timeslot #n-1 |
Timeslot #n |
Timeslot #n+1 |
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DP2P Invite |
DP2P Confirm |
DP2P Response |
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The predefined length of the DP2P Response Handshake timeslots is 110 ms (DP2P_TIMESLOT). The non‑zero field SlotLength in the DP2P Request can be used to specify a different length.