140
EOT (1)
EOT (2)
EOT (3)
3 seconds
3 seconds
EOT (10)
3 seconds
or more

ACK

EOT
EOT
EOT
3 seconds
3 seconds
Phase 3 with iterated EOT transmission due to no response or invalid
response
If the sending station receives no response or any invalid response from the
receiving station in response to an EOT sent, it iterates sending of an EOT at three-
second intervals up to ten times.
If the sending station receives an ACK before sending an EOT ten times, it termi-
nates the message transmission normally and releases the data link.
Receiving
station
Sending
station
Normal
termination
Abnormal termination of phase 3
If the sending station receives no ACK from the receiving station within three
seconds from the 10th EOT, it terminates the message transmission abnormally
and releases the data link.
Sending
station
Receiving
station
Abnormal
termination