Mitsubishi Electric Melsec QJ71LP21 - Message Sending Function Using the Logical Channel Numbers

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MELSEC-Q
7 APPLICATION FUNCTIONS
7.4.4 Message sending function using the logical channel numbers
The message sending function using the logical channel numbers
1
is useful when
there are many kinds of information and the receiving station side needs to selectively
receive only some of the send messages.
The sending station side is equivalent to a broadcast station that delivers messages to
logical channels, and the receiving station side is equivalent to a television receiver in
an ordinary household that can switch between logical channels.
The sending station side executes the transient transmission by attaching an address
for a logical channel without specifying a specific station number (although
specification of station numbers is also possible). All the other stations on a single
network receive the send data, and then the receiving stations delete the messages
except for the messages whose logical channel number matches with the one set by
the receiving stations.
1: The logical channel refers to an input channel that can be changed by the
sequence program. There are eight physical input channels, but up to 64
channel numbers can be set by modifying the link special register value.
(1) Visual representation of the function
When the message is sent from the network module
D
to logical channel 9, only
the network modules
A
,
C
where logical channel 9 has been set can receive it.
The network module
B
does not receive it since logical channel 9 has not been
set there.
QCPU QJ71BR11
QCPU QJ71BR11
8
3
Channel 1
2
channel 14
channel 12
channel 10
channel 9
Receive side
Logical
channel 15
J.RECV
Receive
command
Device memory
QCPU
QJ71
BR11
8
3
2
Create data
command
Send
message
data creation
J.SEND
Send
command
Send message data
Device memory
QCPU QJ71BR11
QCPU QJ71BR11
QCPU
QJ71
BR11
Power
supply
module
QCPU
QJ71
BR11
QCPU
QJ71
BR11
B
A
C
D
8
3
Channel 1
2
channel 14
channel 12
channel 10
channel 13
Receive side
Logical
channel 15
J.RECV
Device memory
8
3
Channel 1
2
channel 14
channel 12
channel 16
channel 9
Receive side
Logical
channel 15
J.RECV
Device memory
Power
supply
module
Power
supply
module
Power
supply
module
Receive
command
Receive
command
Channel 1
channel 9
channel 10
channel 12
channel 15
Receive side
Logical
channel 1