Omron CJ1W-FLN22, Руководство по эксплуатации, Страница: 92 / 277

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Data Link Overview Section 5-1
A node can also use the whole Common Memory as a receiving area only.
3. Areas 1 and 2
Common Memory is configured of two data areas: Area 1 and Area 2. The
area is accessed by the word address. Area 1 consists of 0.5 Kword, and
Area 2 consists of 8 Kwords. The transmission area is defined by its first
word and size.
4. Data Concurrency
In cyclic transmission, the transmission data is fragmented into multiple
frames depending on the size of the data. The following procedure ensures
concurrency of the Common Memory for each node.
5. Transmission Timing
When there is a data transmission request from the upper layer, the cyclic
data from the local node is copied into the buffer, prepared for transmis-
sion, and then transmitted in order. If the size of the data held in the trans-
mitting node is greater than the maximum capacity that can be sent in one
frame (1,024 bytes), the data in the buffer is fragmented into multiple
frames before transmitting.
6. Refresh Timing when Receiving Data
As soon as the receiving node has received all the cyclic data from one
node, the relevant area in Common Memory is refreshed in synchroniza-
Common Memory of node 01
Node 02
Node 05
(Transmitting)
(Transmitting) (Receiving)
(Receiving)
(Receiving)
(Receiving)
2
15
2
0
First word
Size
2
15
2
0
First word
Size
0
0
0x1ff
0x1f f f
Area 1 Area 2
Transmission
area Transmission
area