Mitsubishi MELSEC QJ71C24, User Manual

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MELSEC-Q
5 DATA COMMUNICATION USING THE MELSEC COMMUNICATION
PROTOCOL
5 DATA COMMUNICATION USING THE MELSEC COMMUNICATION
PROTOCOL
This chapter explains an overview of the MELSEC communication protocol (hereinafter
abbreviated as the MC protocol). See the following manual for a detailed explanation
of the data communication functions that are available when using the MC protocol.
MELSEC-Q/L MELSEC Communication Protocol Reference Manual (SH-080008)
5.1 Data Communication Functions
The MELSEC protocol (MC protocol) is a communication system for the Q series
programmable controllers. Using this protocol, the external devices can read or write
device data and programs for the programmable controller CPUs via the Q series C24
or Q series Ethernet interface module.
Any external devices on which application programs can be installed and which can
transmit and receive data in accordance with the MELSEC programmable controller
protocol can communicate with the programmable controller CPUs using the MC
protocol.
5.1.1 Accessing the programmable controller CPUs using the MC protocol
This section describes the main functions for accessing the programmable
controller CPUs using the MC protocol.
(An overview of the data communication functions using the MC protocol is
provided in Section 3.4).
With the exception of the on-demand function described below, the Q series C24
sends and receives data based on commands from the external devices.
Thus, the programmable controller CPU side does not require sequence
programs for data communication.
(1) Data read/write
This function reads and writes data from/to the programmable controller CPU
device memory of the local-station or other station on the CC-Link IE Controller
Network, CC-Link IE Field Network, MELSECNET/H, MELSECNET/10 as well as
the intelligent function module buffer memory.
By reading and writing data, the programmable controller CPU operation monitoring,
data analysis and production management can be performed on the external device
side.
Also, production directions can be executed on the external device side.
(2) File read/ write
This function reads and writes files stored in the programmable controller CPU
such as sequence programs and parameter files. By reading and writing files, file
management for the GX Configurator-SC and the QnACPUs of other stations can
be performed on the external station side.
Also, execution programs can be changed (replaced) from the external device side.
(3) Remote control of the programmable controller CPU
This function executes remote RUN/STOP/PAUSE/latch clear/reset operations.
Remote operations of the programmable controller CPU can be performed from
the external device side using the programmable controller CPU remote control
function.
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