Mitsubishi Electric MELSEC Q Series User Manual page 224

(2) Channel
Each network module has a data area used for message communication, called a "channel".
By using multiple channels, simultaneous access from the host to multiple other stations, and simultaneous
reading and writing to the same module are allowed. The number of channels varies depending on network types.
(3) Internal buffer for message reception
The C Controller module uses the internal buffer for message reception to store specified data. Internal buffer for
message reception may store up to 128 reception data sets per network module. If data are received when the
buffer area has been full of received data, they will be discarded instead of being stored in the buffer. Therefore,
read received data before the number of the data stored in the internal receive buffer exceeds 128.
In message reception, data of the channel specified in the message receiving function are retrieved from the data
stored in the internal buffer.
User program
ret = QBF_RECV();
or
ret = mdReceiveEx();
222
C Controller module
Message reception
Internal buffer
CC-Link IE Controller
Network module
1st
2nd
127th
128th
(for 2nd)
1st
2nd
127th
128th
(for 3rd)
1st
2nd
127th
128th
(for 4th)
1st
2nd
127th
128th
CC-Link IE Controller Network module (1st module)
Channel 1
Channel 2
Channel 3
Channel 4
Channel 5
Channel 6
Channel 7
Channel 8
CC-Link IE Controller Network
module (2nd module)
CC-Link IE Controller Network
module (3rd module)
CC-Link IE Controller Network
module (4th module)