Panasonic FPS Series, User Manual

Page: 190 / 332

FP Σ User's Manual
8.5 MEWTOCOL-COM
173
8.5.1 Operation Outline for MEWTOCOL-COM Slave
Instructions issued by the computer to the PLC are called commands. Messages sent back to
the computer from the PLC are called responses. When the PLC receives a command, it
processes the command regardless of the sequence program, and sends a response back to
the computer. Communication is carried out in a conversational format, based on the
MEWTOCOL-COM communication procedures. Data is sent in ASCII format. The computer
has the first right of transmission. The right of transmission shifts back and forth between the
computer and the PLC each time a message is sent.
1
1
2
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3
3
4
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5
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67
7
8
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Start
code
Start
code
Text
Text Source
Computer
Transmission program Reception processing program
Command message
Response message
The type of command
Any settings and data
required in order to
execute the command
The command and data
are sent to the PLC with
the specified station
number
The station number of
the PLC that sent the
response
Confirmation of whether
or not the processing was
carried out successfully
The type of command
processed
If an error occurred and
the command could not
be processed success-
fully, the content of the
error
A response is returned and
processed by the computer
(e.g. the computer retrieves
the data that was sent.)
If the command was
used to read data, the
data that was read
Check
code End
code
Destina-
tion Check
code End
code
The station number of
the PLC to which the
command is being sent
MEWTOCOL-COM communication between the FP Σ and a computer