Data Communication; Formats And Applications Of The Data Communication Frames - Mitsubishi Melsec-L Series User Manual

8.1 Data Communication

8.1.1 Formats and applications of the data communication frames

The MC protocol uses the following communication frames for data communication.
The external device must communicate data in the data format appropriate to the MC
protocol.
QnA compatible 3C frame Formats 1 to 4
QnA compatible 4C frame Format 5
QnA compatible 2C frame
A compatible 1C frame
(1) QnA compatible 3C and QnA compatible 4C frames
(2) QnA compatible 2C frame
(3) A compatible 1C frame
The message format and control procedure are the same as when accessing the
programmable controller using the conventional modules listed below.
• A series computer link module
• QnA series serial communication module
• Q series C24
The external device side can access the L series C24 with a program used for
accessing the programmable controller via a conventional module.
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Available communication frame
Formats 1 to 4
These frames are mainly used to access all devices and files of the Q/L/QnACPU
from the external device.
It is also possible to access ACPU devices.
This frame can access the device memory of LCPU station (host station) on
which the L series C24 is connected and Q/L/QnACPU stations linked by
multidrop connection.
This frame has the same message structure as when accessing the
programmable controller CPU using an A series computer link module.
POINT
8 DATA COMMUNICATION USING THE MC PROTOCOL
Code of communication
data
ASCII code
MELSEC-Q/L MELSEC
Binary code
Communication Protocol
Reference Manual
ASCII code
Reference
8
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