ER-A440 (serv.man6). ERA440 Option Service Manual - Sharp ECR Service Manual (repair manual). Page 9

      STATE

Initial

After sending ID ENQ

After sending text

EVENT   

0

1

2

ENQ

—

—

—

ACK

—

Sends text and goes to 2. 

Sends EOT and goes to 3.

NAK

—

—

Resends the text and then goes to 2.
If the host has resent the text two times, it goes to 0.
(ERROR END)

EOT

—

—

The host goes to 0.
(ERROR END)

TEXT

—

—

—

TIME-UP

—

Resends ID ENQ and then goes to 1.
If the host has resent ID ENQ two times, it 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)

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

After sending ACK

After sending NAK

EVENT   

3

4

5

ENQ

Sends ACK and goes to 4.

After the host has received ENQ, resends ACK and goes to
4.
After the host has received TEXT, ignores the ENQ.

—

ACK

—

—

—

NAK

—

—

—

EOT

The host goes to 0
(ERROR END)

After the host has received TEXT, goes to 0.
(Normal end)
After the host has received ENQ, goes to 0.(ERROR END)

The host goes to 0.
(ERROR END)

TEXT

—

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 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)

TIME-UP

Resends EOT and goes to 3.
If the host has resent the EOT two times, it goes to 0.
(ERROR END)

The host goes to 0.
(ERROR END)
Time-up is 7 seconds

The host goes to 0.
(ERROR END)
Time-up is 7 seconds 

KEY ENTRY

—

—

—

Time-up: Two second after sending of EOT.

 – 8 –