Mitsubishi Electric Q12DCCPU-V - Page 195

5
ACCESS VIA NETWORK MODULES
5.4 CC-Link IE Controller Network Module Access Function
5.4.1 Message communication
5 - 41
1
OVERVIEW
2
SYSTEM CONFIGURATION
3
SPECIFICATIONS
4
FUNCTIONS
5
ACCESS VIA NETWORK MODULES
6
PREPARATORY PROCEDURES AND SETTING
7
I/O NUMBER ASSIGNMENT
8
MEMORIES AND FILES
Remark
For the bus interface functions and MELSEC data link functions, refer to the
following manual.
C Controller Module User's Manual (Utility Operation, Programming)
(3) Message communication example
The following a message communication example.
1) The C Controller module sends a message using a message sending function
in the user program.
2) Station No.4 sends the message, by the message sending function in the user
program and using channel 3, to the target station data storage channel 5 of
station No.5.
3) The C Controller module (another station) automatically checks the message
stored in station No.5, and stores the message into its own internal receive
buffer.
4) The C Controller module (another station) reads the message from the internal
receive buffer using a message receiving function.
POINT
Pay attention to the following when sending a message to a CC-Link IE controller
network module controlled by a programmable controller CPU.
When sending data twice to the same channel of the receiving station with ACK
set, execute the second transmission after the receiving station has read out the
first data by the RECV instruction.
Failure to do so will cause an error. If an error is detected, retry the transmission
after a little while.
Figure 5.39 Message communication example
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
ret = QBF_RECV();
ret = mdReceive();
ret = QBF_SEND();
ret = mdSend();
CC-Link IE controller network
CC-Link IE controller network
1)
2)
3)
4)
C Controller module
User program
or
module (Station No.4)
Network No.1
module (Station No.5)
C Controller module
(another station)
User program
Internal
message
receive buffer
or
1st
2nd
127th
128th
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8