Mitsubishi Electric QJ71DN91 User Manual page 135

7 PROGRAMMING FOR EXECUTING THE MASTER FUNCTION
(4)
Programmable controller CPU
1)Transmit request
M0
7)
D0
2)
Transmit
D1
data
D2
Transmitting node (QJ71DN91 master)
1)
\
Transmit complete Transmit request
flag: 703H flag: 903H
\
Transmit complete
flag: 703H
Receiving node (QJ71DN91 slave)
4)
\ \
Receive complete Receive completion
flag: B03H notification
flag: C03H
\
Receive complete
flag: B03H
7 - 2
When handling transmit/receive data of multiple words, pay attention to the
following:
Consistency of 1-word or 2-word (for double-word modules) is guaranteed for
transmit/receive data.
When data of three words or more are handled, new and old data may be mixed
in units of one word.
Therefore, confirm correct data transfer using a method such as providing a
handshake area at each end of transmit/receive data areas, as shown in the
following example.
QJ71DN91 master
Master function
receive data
700
H
701
H
702
H
703 (Transmit complete flag)
H
Master function
transmit data
900
H
901
Transmit data
H
902
H
3)
903
(Transmit request flag)
H
\
QJ71DN91 slave Programmable controller CPU
Slave function
transmit data
C00
H
C01
H
C02
H
6)
(Receive completion
C03
H
notification flag)
Slave function
receive data
B00
H
5)
B01 Receive data
H
B02
H
4)
B03
(Receive complete flag)
H
2)
\
Stores transmit data in Master
function transmit data area.
Transmit Master function
data transmit data: 900H
3)
\
Sets Transmit request flag.
Transmit
request
flag: 903H
7) \
Resets Transmit request flag.
Transmit
request
flag: 903H
5)
\
Reads receive data from Slave
function receive data area.
Slave function Receive data
receive data
:B00H
6)
\
Sets Receive completion
notification flag.
Receive
completion
notification
flag
:C03H
\
Resets Receive completion
notification flag.
Receive
completion
notification
flag
:C03H
MELSEC-Q
D100
D101 Receive data
D102
7 - 2
7