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5.3 MELSECNET/H Module Access Function
5.3.1 Message communication
5
ACCESS VIA NETWORK MODULES
(a) Internal buffer for message reception
1) The internal buffer for message reception stores the data received from the
MELSECNET/H module controlled by the C Controller module.
2) The internal receive buffer has the areas for four MELSECNET/H modules,
and up to 128 received data can be stored in each area.
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.
3) In message reception, data of the channel specified in the message receiving
function are retrieved from the data stored in the internal buffer.
Figure 5.11 Internal buffer for message reception
ret = QBF_RECV();
ret = mdReceive();
(For second module)
(For third module)
(For fourth module)
1st
2nd
127th
128th
1st
2nd
127th
128th
1st
2nd
127th
128th
1st
2nd
127th
128th
MELSECNET/H module (Second module)
MELSECNET/H module (Third module)
MELSECNET/H module (Fourth module)
C Controller module
for message reception
MELSECNET/H module
Internal buffer
User program
or
Logical channel (Channel 1)
Logical channel (Channel 2)
Logical channel (Channel 3)
Logical channel (Channel 4)
Logical channel (Channel 5)
Logical channel (Channel 6)
Logical channel (Channel 7)
Logical channel (Channel 8)
MELSECNET/H module (First module)
Summary of Contents for Q06CCPU-V
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