112
What Are Data Links?
Section 5-1
Using Offsets
For automatically set data links, all of the send words transmitted by a node
are received by other nodes with no change in size. For manually set data
links, the size of a receive area can be restricted by specifying a number of
words from the beginning word of the words sent by another node.
However, the above system does not guarantee that only the desired words
will be received and therefore the receive node may receive unnecessary
data.
Offsetting enables specification of a more specific range of receive data by
indicating both the number of words and the starting word position from the
beginning of the area. The offset refers to the starting word position counted
from the beginning of the area.
Offsetting Image
Application Example of
Using Offsets
In the following example, the send data from node 1 is split into three parts
and each part is received by a different node, i.e., each of the other nodes
receives only part of the send data from node 1. This enables effective use of
data link memory areas without wasting space. In this way, a type of message
service (i.e., specific data to a specific node) can be achieved through data
links.
Manually set
data links
A node can specify the number
of words to receive from the
beginning send word.
# 1
# 2
# 3
# 2
# 3
# 2
# 3
# 3
# 2
# 1
# 1
# 3
# 2
# 1
# 1
# 3
# 2
# 1
# 1
# 2
# 3
# 1
# 2
# 3
Automatically set
data links
# 1
# 2
# 3
# 3
# 1
# 3
# 2
# 2
# 1
# 1
# 2
# 3
Offset from the beginning
Number of words to be received
Restricted reception
from node 1 by
specifying an offset
Restricted reception
from node 2 by
specifying an offset
#1 Data
I only need this.
I need all of it.
#1 Data
Содержание C200HW-CLK21
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Страница 12: ...xiii TABLE OF CONTENTS Index 367 Revision History 373 ...
Страница 13: ...xiv ...
Страница 19: ...xx ...
Страница 57: ...32 Application Precautions Section 1 5 Example CX Programmer Response Timeout Setting ...
Страница 69: ...44 Message Service Procedure Section 2 2 ...
Страница 111: ...86 Constructing Networks with Repeater Units Section 3 4 ...
Страница 154: ...129 Setting Data Links Section 5 2 Device Information Setting Data Link Tables ...
Страница 261: ...236 Response Codes Section 6 7 ...
Страница 297: ...272 Message Delay Times Section 8 4 ...
Страница 353: ...328 Handling Precautions Section 9 6 ...
Страница 364: ...339 Changing the Data Link Tables with Active Data Links Section 10 2 ...
Страница 365: ...340 Changing the Data Link Tables with Active Data Links Section 10 2 ...
Страница 369: ...344 Standard Models Appendix A ...
Страница 391: ...366 Using the Relay Terminal Block Appendix C ...
Страница 397: ...372 Index ...
Страница 401: ...376 Revision History ...