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Communications (Serial and Parallel)
16.11 Computer Link
Write to PLC command
The basic format for the command to write to the PLC is as follows.
%EE#WDD000010000212345678
Command:
Fixed unit No.
Write command
Data code
Start register
Response:
%EE$WDBCC
As the maximum number of bytes for one PLC frame is 118, when the
amount of data (number of words) to be written exceeds 24, the format for
the command is as follows.
Example:
To write 64 words starting from the data register number 15.
Command:
Response:
Command:
Response:
Command:
Response:
Read from PLC command
Use the following command to read from the PLC.
%EE#RDD0000100001 **
Command:
Fixed unit No.
Read command
Data code
Start register
%EE$RD1234BCC
Response:
16 − 64
C
**
R
Ignore BCC specification
Data
Data
End register
C
(Command receive complete)
R
%EE#WDD00015000781234........5678
Data 1
C
(transmit request)
%EEBCC
&
R
C
%EE26data block
** &
R
%EEBCC
(transmit request)
&
C
R
C
(third time)
%EE14data block** &
R
C
(command receive complete)
%EE$WDBCC
R
C
R
Ignore BCC specification
End register
C
(command receive complete)
R
Query data (reversal of upper and lower positions is required)
C
&
**
(first time)
R
Delimiter
Data 24
(second time)
OCR Type A230
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