Communication Format - Sharp IV-S30J User Manual

17-3 Communication format

The communication formats of the commands and responses between the IV-S30J and a personal
computer are outlined below.
Command
Station
:
No.
Response
:
*1 Station No.: 00 to 7F
*2 Processing code and text
- They depend on the contents of communication. - See pages 17-1 and 17-7 and after.
- On abnormal termination, no text is provided.
*3 Termination code
The termination code is a 2-digit hexadecimal number.
- When an output is sent through the general purpose serial I/F, 00
termination.
- On abnormal termination, a code other than 00
*4 Checksum code (SC
To improve the reliability of the transmitted data, in addition to a parity check, error detection by a
checksum is used for error detection.
When the IV-S30J does not need to complete a checksum for error detection, use an @ (at sign:
ASCII code 40
[Error detection using a checksum]
The ASCII code for each data byte, from the processing code to the end of text (prior to the
checksum code), is added. The final value is compared to the checksum code which is treated the
same way. If the two values are identical, the command is considered to be valid. I/F they are not
identical, an error has occurred during transmission.
Command
:
Response
:
...............
*2
*1
Processing
Station
code
No.
Station
RC
No. RC
L
H
*3
Termination
*1
Station
code
No.
*2
Processing code
(H)
(H)
and SC )
H L
) in each of the checksum codes SC
(H)
Value increment range
for checksum
Station
No.
Station
Processing
No.
code
Value increment range
for checksum
Station
RC
No. RC
H L
Station Termination
No. code
Processing code
Communication (General Purpose Serial Interface)
SC
SC
CR
L
H
Terminator
*2
*4
Text
Checksum code
...............
SC
SC CR
L
H
*2
Text
*4
Checksum code
is sent. - See page 19-3.
(H)
and SC included in the command.
H L
SC
SC CR
H L
Terminator
Text Checksum code
SC SC CR
H L
Text
Terminator
Checksum code
17-5
Terminator
is sent on normal
(H)
17