6 DATA COMMUNICATION USING THE NON PROCEDURE PROTOCOL MELSEC-Q

6.2.2 Arrangement and contents of the transmission area and the transmission data

This section explains the arrangement and contents of the transmission area and the transmission data for performing data transmission using the non procedure protocol.

(1) Transmission area

The transmission area is a memory area for storing the data and the data count that are transmitted from the PLC CPU to the external device via the Q series C24. By default, the transmission area is assigned to addresses 400H to 5FFH (CH1 side) and 800H to 9FFH (CH2 side).

CH1 side

 

 

 

address

Buffer memory

400H

Transmission area

 

Transmission data count

 

401H

 

storage area

 

 

 

 

 

to

 

 

Transmission data

 

 

storage area

 

 

 

5FFH

 

 

 

 

 

 

(Default setting)

 

 

• The unit of transmission data count (words/bytes)

is in accordance with the word/byte units designation in GX Configurator-SC.

•The transmission data count designated with the OUTPUT instruction is written.

•The transmission data designated with the OUTPUT

instruction is written.

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