Omron CJ1W-FLN22, Operation Manual, Page: 91 / 277

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Data Link Overview Section 5-1
ing node management table in ascending order. The node with the largest
node number in the network passes the token to the node with the smallest
node number in the network.
2. Common Memory
The concept of Common Memory is as follows:
a) Common Memory provides a service that functions as shared memory
between nodes transmitting cyclic data.
b) Two areas (Area 1 and Area 2) are assigned for each node.
c) When the area transmitted by a node exceeds the transmission size
limit for a single frame, which is 1,024 bytes, the data is fragmented
into multiple frames and then transmitted.
d) In the case of item c), when the fragmented data frames are received,
the Common Memory is not refreshed until all frames from the one
node have been received, thereby ensuring the concurrence of the
data at individual nodes.
e) The capacity reserved as Common Memory for communications in a
single node is a fixed size of 8 Kbits + 8 Kwords = 8.5 Kwords.
f) Within Common Memory, the size of the transmission area of Area 1
and Area 2 for each node can be set freely within the maximum area
range.
g) By broadcasting data, each node in the network shares the same data
for a specific period. Each node in the FL-net network is allocated a
specific transmission area that does not overlap with that of the other
nodes, and data is exchanged among them. In Common Memory op-
erations, the transmission area allocated to one node is the receiving
area for the other nodes.
Common Memory of node 01 Node 02 Node 03 Node 04
(Transmitting)
(Transmitting)
(Transmitting)
(Transmitting)
(Receiving)
(Receiving)
(Receiving)
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(Receiving)
(Receiving)
(Receiving)
(Receiving)
(Receiving)
(Receiving)
(Receiving)
(Receiving)
(Receiving)