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Specifications
(5) Check code
• This is a CRC (Cyclic Redundancy Check) to detect errors using a generating polynomial of
hamming codes.
• The CRC should be created so that it targets all of the text data from the header to the last
text character.
• CRC is a value given by replacing the result of calculation by CRC-16-CCITT with character
text. It is normally part of the calculation program and is created automatically.
(6) Terminator (end code)
The message should end with "CR" (ASCII code: H0D).
•
If no response is returned, the communication format may not be correct, or
the command may not have arrived at the PLC, or the PLC may not be
functioning. Check if the specified connection is ON, or if the connection
information setting is correct.
•
If the response contains an "!" instead of a "$", the command was not
processed successfully. The response will contain a communication error
code. Check the meaning of the error code.
Station no. and command name are always identical in a command and its
•
corresponding response (see below). This makes the correspondence
between a command and a response clear.
Command
Response
8-14
>
@
E
E
E
Same
Same
>
@
E
E
E
0
0
#
0
0
M
Same
0
0
$
0
0
M
M
R
D
C
R
M
R
D
C
R
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