Mitsubishi MELSEC Q Series User Manual

4
FUNCTIONS
4.4 MELSECNET/H Module Access Function
4.4.1 Message communication
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OVERVIEW
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SYSTEM CONFIGURATION
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SPECIFICATIONS
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FUNCTIONS
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INSTALLING / UNINSTALLING
(3) Message communication functions
The following functions are available for message communication.
Remark
Refer to Chapter 10 for details of the bus interface functions and MELSEC data
link functions.
(4) Message communication example
The following gives a message communication example.
1) The C Controller module sends a message according to the message sending
function in the user program.
2) Station No.4 sends the message to the target station storage channel 5 (logical
channel 5) of Station No.5 using its Channel 3 according to the message
sending function of the user program.
3) The C Controller module (other station) automatically confirms the message
stored in Station No.5, and stores it into its own internal buffer for message
reception.
4) The C Controller module (other station) reads the message from the internal
buffer for message reception according to the message receiving function of
the user program.
Table4.6 Message communication function list
Function
Function
name
Description
Message
transmission
QBF_SEND Sends a message to the other station via a MELSECNET/H
module. (Equivalent to the SEND instruction)
mdSend
Message
reception
QBF_RECV Receives a message from the other station via a
MELSECNET/H module. (Equivalent to the RECV instruction)
mdReceive
Figure 4.13 Message communication example
Logical channel 1 (Channel 1)
Logical channel 2 (Channel 2)
Logical channel 3 (Channel 3)
Logical channel 4 (Channel 4)
Logical channel 5 (Channel 5)
Logical channel 6 (Channel 6)
Logical channel 7 (Channel 7)
Logical channel 8 (Channel 8)
ret = QBF_RECV();
ret = mdReceive();
ret = QBF_SEND();
ret = mdSend();
MELSECNET/H
MELSECNET/H
1)
2)
3)
4)
C Controller
module
User program
or
module (Station No.4)
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
Network No.1
module (Station No.5)
C Controller module
(other station)
User program
Internal buffer
for message
reception
or
1st
2nd
127th
128th

Mitsubishi MELSEC Q Series Specifications

General

Brand	Mitsubishi
Model	MELSEC Q Series
Category	Controller
Language	English