beautypg.com

Phase 2 with nak – Denso BHT-6000 User Manual

Page 110

background image

95

Chapter 3. Communications Operations of BHT-6000

NAK

NAK

NAK

NAK

NAK

ACK

Phase 2 with NAK

If the sending station receives a NAK from the receiving station in response to a
transmission block containing text data m, it sends that transmission block again
immediately as shown below.

If the sending station receives an ACK before receiving a NAK 10 times in succes-
sion, it continues the subsequent message transmission.

Sending
station

Receiving
station

Data text m

Data text m

Data text m

Data text m+1

If the sending station receives a NAK 10 times in succession or it fails to send a
same transmission block, it shifts to phase 3 to terminate the message transmis-
sion abnormally. Even if the phase 3 terminates normally, the transmission results
in an abnormal end.

Sending
station

Receiving
station

To phase 3.

Occurrence

of an error

Data text m (10)

Data text m (2)

Data text m (1)