4.1.3 Message 3
Node A sends Message 3 to the receiver, Node B. This message is one Data frame (section 2.2.2) in length, is marked as reliable, and will drop the first transmission.
-
Message 3: DATA FRAME Flags: STA, EOM, RLY messageid: 2, sequence: 4, serial:0
If Message 3 is dropped, but the sender, Node A, still sends Message 4 (section 4.1.4) to the receiver, Node B, this would result in the following.
-
Message 4: DATA FRAME: 1 Flags: STA messageid: 3, sequence: 5, serial: 0 Message 4: DATA FRAME: 2 Flags: EOM messageid: 3, sequence: 6, serial: 1
This can trigger a NACK on the receiver, Node B.
The receiver, Node B, sends back a NACK to the sender, Node A.
-
Flags: NACK messageid: 2, sequence: 4, nNACK: 0, no NACK mask present, bytes received 8954
In response to the NACK, the sender, Node A, attempts a retransmission of Message 3 to Node B.
-
Message 3: DATA FRAME (retry) Flags: STA, EOM, RLY messageid: 2, sequence: 4, serial: 1