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(5) Check code
This is a CRC (Cyclic Redundancy Check) to detect errors using a generating polynomial of
hamming codes.
This 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 ASCII
code. 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).
NOTE
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 to make sure all of the communication specifications
(e.g. baud rate, data length, and parity) match between the computer and
the PLC.
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
>
@
E
E
E
Same
Same
>
@
E
E
E
7.3 MEWTOCOL7-COM Format
0
0
#
0
0
M
Same
0
0
$
0
0
M
M
R
D
C
R
M
R
D
C
R
7-11
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