Features Of The Melsec Communication Protocol - Mitsubishi MELSEC Q Series Reference Manual

1.2 Features of the MELSEC Communication Protocol

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This section explains the features of the MC protocol.
(1) The data communication using the MC protocol is a function that enables the
reading/writing of data from/to the programmable controller CPU in order to
control and monitor the programmable controller equipment from the external
device side.
Reading/writing device data and program files for the programmable controller
CPU and controlling the programmable controller CPU status (remote
RUN/STOP) can be performed from the external devices (personal computer,
indicator, etc.)
(a) Reading and writing data
By reading/writing data to/from the device memory of the programmable
controller CPU and the buffer memory of the intelligent function modules,
the following control operations can be performed:
Data read and write operations can also be performed for A/QnA series
programmable controller CPUs (other stations) and intelligent function
modules.
1) Reading data
Operation monitoring, data analysis, production control, etc. can be
performed from the external device side.
2) Writing data
Production instructions, etc. can be issued from the external device
side.
(b) Reading and writing files
By reading and writing files for sequence programs and parameters stored
in the programmable controller CPU, the following control operations can
be performed:
1) Reading files
File management for the local station's QCPU/LCPU and other station'
QCPU/LCPU/QnACPU can be performed from the external device
side.
2) Writing files
Programs such as execution programs can be modified (replaced) by
writing file data stored in the external device to the programmable
controller CPU as needed.
(c) Remote control of the programmable controller CPU
The programmable controller CPU can be remotely controlled from the
external device by performing remote RUN/STOP/PAUSE/LATCH
CLEAR/RESET operations.
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