Link Communications; Link Allocation; Conceptual Diagram Of Link Communications - YASKAWA MP920 User Manual

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.
MP920
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.
13FF
0FFF
0BFF
07FF
03FF
0000
The I/O registers other than the transmitted registers at each local station will be the recep-
tion areas from remote stations.
Machine Controller
(IB, IW, IL, LFhhhh)
5,120 words (0000 to 13FF)
ST#1
Transmitted
Transmitted
Local
2-3
Input Registers
(OB, OW, OL, OFhhhh)
5,120 words (0000 to 13FF)
Token Cycle
ST#2 ST#3
Transmitted
Local Local

2.2 Link Communications

Output Registers
ST#4
Transmitted
Local
2