Sharp ER-A440 Service Manual page 23

2. Transmission control procedure matrix
1) Down-loading matrix for the host
STATE
EVENT
ENQ
ACK
NAK
EOT
TEXT
TIME-UP
KEY ENTRY Sends ID ENQ and goes to 1.
Time-up: One second after sending of ID ENQ.
Four seconds after sending of text.
Initial
0
—
Sends text and goes to 2.
—
—
—
—
Resends ID ENQ and then goes to 1.
If the host has resent ID ENQ two times,it sends EOT and
—
goes to 0.
(ERROR END)
After sending ID ENQ
1
—
—
—
—
—
After sending text
2
—
Sends text and goes to 2.
Sends EOT and then goes to 0.
(Normal end)
Resends the text and then goes to 2.
If the host has resent the text two times, it sends EOT and
goes to 0.
(ERROR END)
The host goes to 0.
(ERROR END)
—
Resends the text and then goes to 2.
If the host has resent the text two times,it sends EOT and
goes to 0.
(ERROR END)
—