CHAPTER 3 INTERFACE
B-EP
Series
3-39
3.2.8
PRINTER STATE TRANSITION
(TPCL, RECEIPT OR ESC/POS MODE)
Printer state transition
Event
State
Ensuring link
Reception of
the middle
block packet
Reception of
the final block
packet
End of issue
Status
Request
Command
reception
EOT
reception
Time out
CRC error
Framing error
Overrun error
Syntax error
Error during
issuing
Wait state for
the link
S1
NAK
transmission
→
S2
— — — — — — — — —
Wait state for a
packet after the
NAK
transmission
S2
— Normal
ACK
transmission
→
S3
Normal
ACK
transmission
Command
analysis
→
S3
— Normal
Status
transmission
→
S3
End of link
NAK
transmission
NAK
transmission
Error
Status
transmission
→
S4
Error
Status
transmission
→
S4
— Error
Status
transmission
→
S4
→
S1
→
S1
→
S2
→
S2
→
S1
Wait state for a
packet/EOT
after the ACK
transmission
S3
— ACK
transmission
ACK
transmission
Command
analysis
EOT has
been
received.
ACK
transmission
Status
transmission
Normal
command
ACK
transmission
if the issue is
completed.
End of link
(NOTE 1)
NAK
transmission
NAK
transmission
→
S1
→
S1
If the issue is
not completed
→
S3
→
S3
→
S3
EOT has not
been received
→
S3
→
S3
Status
request
→
S1
→
S1
→
S2
→
S2
→
S1
Wait state for
an EOT after
the status
transmission
S4
— Status
transmission
→
S4
Status
transmission
→
S4
— Status
transmission
→
S4
Clear of error
→
S1
End of link
→
S1
— Timer
reset
→
S4
→
S1
NOTE:
An ACK for the command process end is also sent, when the time out occurs during the wait
state for an EOT.
Host state transition
Event
State
NAK reception
ACK reception
Status
reception
Time out
(NOTE 1)
CRC error
Framing error
Overrun error
Activation of
transmission to
the printer
Wait state for a
NAK of the link
request
S1
Command
transmission
→
S2
→
S1
→
S1
→
S1
→
S1
—
Wait state for
an ACK/status
after the
command
transmission
S2
Packet
retransmission
→
S2
Middle block
Packet
transmission
→
S2
Final block
EOT
transmission
→
S3
or
→
S4
EOT
transmission
→
S4
→
S4
→
S4
—
Wait state for
an ACK after
the EOT
transmission
S3
—
→
S4
→
S4
→
S4
→
S4
—
Key entry mode
S4
→
S4
→
S4
→
S4
— —
→
S1
NOTE:
The retry count is arbitrarily determined by the host.