Yaskawa MP920 Communications Module - Manual (Page 28)

2.2 Link Communications
2-3
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2.2 Link Communications
This section explains link communications.
Link communications automatically transfer I/O data (such as relays, coils, and registers)
between Machine Controllers, and operate only between 215IF Modules. Links cannot be used
with 217IF or 218IF Modules. The Machine Controllers transfer data at regular intervals by a
communications mechanism called token passing according to the link allocation map that has
been set in advance.
2.2.1 Link Allocation
MP900-Series Machine Controllers have the following I/O register areas.
Settings are made to map registers in these I/O register areas between the Machine Control-
lers to show how data is to be transferred. This is called Link Allocation. See „Transmission
Parameter Settings under 5.5.4 Setting CP-215 Transmission Definitions for details.
2.2.2 Conceptual Diagram of Link Communications
If we assume, for example, that I/O registers 0000 to 03FF are in a local area for each station
and that registers 03FF to 13FF are used for shared areas, then the link communications
would conceptual appear as shown below.
The I/O registers other than the transmitted registers at each local station will be the recep-
tion areas from remote stations.
Machine Controller Input Registers
(IB, IW, IL, LFhhhh)
Output Registers
(OB, OW, OL, OFhhhh)
MP920 5,120 words (0000 to 13FF) 5,120 words (0000 to 13FF)
13FF
0FFF
0BFF
07FF
03FF
0000
ST#1 ST#2 ST#3 ST#4
Token Cycle
Transmitted
Transmitted
Transmitted
Transmitted
Local Local Local Local