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9.3. Error Detection Processing
With this program, the error detection processing is performed according to the following
descriptions (1) to (3). For information on error codes, refer to 9.8. Error Processing.
(1)Errors at the execution of the PMCR instruction (PMCR instruction errors)
An incorrect communications sequence number and an incorrect memory address, both of
which prevent the execution of the PMCR instruction, are detected as PMCR instruction
errors. If an error occurs, the error code (1519.00 to 03) will be generated to identify the
error, which indicates the port operating status in the CIO area allocated to the SCU.
(2)Errors in communications with the Destination Device (Communications error)
Errors that occur in communications with the Destination Device, such as character
corruption and transmission errors caused by unmatched baud rate setting, are detected as
communications errors. If an error occurs, the Sequence Abort End Completion flag
(1519.10) in the CIO area allocated to the SCU will be turned ON to identify the error.
(3)Errors in the Destination Device (Destination Device errors)
Destination Device errors include a command error, a parameter error, a data error and an
execution failure in the Destination Device. An error is identified in the response data that is
returned from the Destination Device. With this program, an error can be detected by
comparing difference in frames between a receive message in normal (hereinafter referred
to as a "normal message") and a receive message in error (hereinafter referred to as an
"error message"). Refer to 9.6.6. Receive Message Settings for details.
STX
"01"
Normal
message
Send
Node
Start
No.
STX
"01"
Error
message
Send
Node
start
No.
STX
"01"
Error
message
Send
Node
start
No.
Additional Information
For information on the CIO area allocated to the SCU, refer to 9.4.2 Lists of Allocations.
CJ2M-CPU12
CJ1W-SCU42
Serial cable
(1)
"00"
"00"
"03"
Sub
End
MRC
Address
code
"00"
"**"
"03"
"05"
Sub
End
MRC
SRC
Address
code
"00"
"**"
ETX
Sub
End
Send
BCC
address
code
end
Destination Device
(2)
(3)
"05"
"00"
"00"
SRC
MRES
SRES
"**"
"**"
ETX
MRES
SRES
Send
end
**
9．Program
***
ETX
**
Data
Send
BCC
End
**
BCC
52
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