Communication Structure - Mitsubishi Electric MELSEC-L SERIES Basic User Manual

13.2

Communication Structure

This section describes the structure of communications using a random access buffer.
(1) Data flow
The data flow in communications using a random access buffer is as follows. The FROM/TO instructions or
intelligent function module devices are used to access a random access buffer from a CPU module.
CPU module
● Communications can be performed only with connected devices where communications using a fixed buffer in the
"Procedure Exist" control method are set using the connection with Open completion signal of an E71 on.
● Communications are performed asynchronously with the program. If synchronization is required, use communications
using a fixed buffer.
(2) Connected devices where data communications can be performed
Data communications can be performed with the following connected devices:
• Devices in Ethernet where an E71 is connected
• Devices connected using the router relay function
CHAPTER 13 COMMUNICATIONS USING A RANDOM ACCESS BUFFER
Using the FROM/TO
instructions or an
intelligent function module device
E71
Writing data
Random
Read request
access
buffer
Reading data
Connected
device
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