Sharp ER-A440 Service Manual page 24

2) Up-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.
STATE After sending EOT
EVENT
Sends ACK and goes to 4.
ENQ
ACK
NAK
The host goes to 0
EOT (ERROR END)
TEXT
Resends EOT and goes to 3.
TIME-UP If the host has resent the EOT two times, it goes to 0.
(ERROR END)
KEY ENTRY
Time-up: Two second after sending of EOT.
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 goes to 0.
(ERROR END)
3
After the host has received ENQ, resends ACK and goes to
4.
After the host has received TEXT, ignores the ENQ.
—
—
After the host has received TEXT, goes to 0.
(Normal end)
After the host has received ENQ, goes to 0.(ERROR END)
The host checks the text block, if the block is correct, the
host sends ACK and goes to 4.
If it is not correct, the host sends NAK and goes to 5.
—
If transmission cannot be continued, the host sends EOT
and goes to 0.
The host goes to 0.
(ERROR END)
Time-up is 7 seconds
—
After sending ID ENQ
1
—
—
—
—
—
After sending ACK
4
—
—
—
After sending text
2
—
Sends EOT and goes to 3.
Resends the text and then goes to 2.
If the host has resent the text two times, it 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 goes to 0.
(ERROR END)
—
After sending NAK
5
—
—
—
The host goes to 0.
(ERROR END)
The host checks the checks the text block, if the block is
correct, the host sends ACK and goes to 4.
If it is not correct, the host sends NAK and goes to 5.
If transmission cannot be continued, the host sends EOT
and goes to 0.
(ERROR END)
The host goes to 0.
(ERROR END)
Time-up is 7 seconds
—