4. COMMUNICATION PROTOCOL
IMSRM04-E8
31
(3) Data send
Send data in the following formats following the selecting sequence. The data format is the same as
that of polling.
For
c
to
h
,
see 4.1 Polling
.
If the length of send data (from [STX] to [BCC]) exceeds 128 bytes, it is divided into blocks
by [ETB]. In this case, send the succeeding data divided into blocks after [STX].
(4) Acknowledge response [ACK]
If this device receives data sent correctly from the host computer, it sends [ACK] to the host computer.
Then, if there is data to be sent next from the host computer, send it to the device. After the data has
been sent, send [EOT] to terminate the data link.
(5) Negative acknowledge [NAK]
This device sends [NAK] in the following cases. In this case, take necessary measures for recovery
such as re-sending the data on the host computer side.
(6) No response
If this device does not receive the selecting address correctly, it is set to no response. Also, it is set
to no response if it does not receive [STX], [ETB], [EXT], or [BCC] correctly.
(7) Data link termination [EOT]
To terminate the data link when there is no more data to be sent from the host computer or this device
is set to no response, send [EOT] from the host computer.
or
Identifier
Data
BCC
ETB
STX
d
h
f
e
c
Identifier
Data
BCC
ETX
STX
d
h
g
e
c
z
When an error occurs in the line (parity error or framing error)
z
When a BBC check error occurs
z
When there is no specified identifier
z
When the specified identifier is not valid
z
When an error exists in the data format
z
When normal receive data exceeds the setting range
