Mitsubishi Electric Melsec QJ71LP21 Reference Manual page 264

7 APPLICATION FUNCTIONS
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POINT
(1) When sending data to the same channel of the receiving station, execute the
sending after the receiving station reads data using the RECV instruction.
If the sending station sends data to the same channel of the receiving station
before the receiving station reads data using the RECV instruction, an error
will occur.
CPU
(Sending station)
SEND
to
SEND
(2) As the target station of data sending, specify the network number and station
number of the network module or Ethernet module that will receive a request
from the sending station.
: In the following figure, specify the network number and station number of
the first network module.
You cannot execute the SEND instruction after specifying any module
other than the network module or Ethernet module that will receive a
request from the sending station.
: In the following figure, you cannot execute the SEND instruction after
specifying the network number and station number of the second network
module.
(Sending station) CPU
(3) Number of resends ((S1)+7) requires to be set every time an instruction is
executed.
Network module
Channel 3
Error
Network No.1
Network
CPU
module
(Target station)
SEND
MELSEC-Q
Network module
(Receiving station)
Logical channel
(channel 5)
Network No.2
Network Network
module module
(First module) (Second module)
CPU
RECV
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