Mitsubishi Electric A1SJ71DN91 User Manual page 14

1. OUTLINE
(2) Outline of Message Communication
Message communication is a function to read and write slave station attribute data.
An outline of message communication is shown below. See 4.2 Message Communication
Functions for details.
(a) Reading attributes
PLC CPU
Device
D, R
Device
D, R
DN91
TO
Message
communication
command area
FROM
Message
communication
result area
Message
FROM
communication
data area
(Up to 240 byte)
−
1 6
MELSEC-A
Slave station
Class
Instance
Attribute
Attribute
Instance
Attribute
Class
Instance
Attribute
Instance
Attribute
Attribute
Attribute