Specifications

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2.2 Types of Data Communication Functions
The Ethernet module has three types of communication functions: "Communication
using MC protocol", "Communication using fixed buffer" and "Communication using
random access buffer".
The following describes the outline of each communication function.
2.2.1 Communication using MC protocol
The MC protocol is used for reading or writing device data and programs of a PLC
CPU from/to a personal computer via an Ethernet module or a Q series serial
communication module.
On the personal computer side, creating a program for data transfer with MC protocol
enables an easy access to the PLC CPU.
On the PLC CPU side, there is no need to create a communication program.
POINT
When performing data communication using the MC protocol, refer to the Q
Corresponding MELSEC Communication Protocol Reference Manual.
(1) MC protocol functions
(a) Reading/writing PLC CPU data
This function allows data reading from or writing to the PLC CPU device
memory of the station (local station) connected to the Ethernet network
system or another station on the MELSECNET/H, MELSECNET/10 as well
as the intelligent function module buffer memory.
By reading and writing data, the PLC CPU operation monitoring, data
analysis and production management can be performed on a personal
computer.
Also, production instructions can be executed from the personal computer.
Read
PLC CPU
Write
Personal computer
Reading/Writing to
device memory/buffer
memory is available