Hitachi Hidic EH-150 EH-OLNK Applications Manual page 15

2) Link area identification
(
When two optical type CPU link modules have been installed, the first and second link areas are identified in
accordance with their installation position. The slots are counted in 0, 1, 2 sequence from the right-hand side
of the CPU, and the CPU link module with the smallest number is assigned as the first unit, with the other
unit assigned as the second CPU link module. The first CPU link occupies the first link area, and the second
CPU link occupies the second link area. When only one unit has been installed, it is assigned to the first CPU
link area.
Note: Link modules can only be installed into slots #0, #1 and #2.
An example of a CPU link system configuration is shown in figure 4.5.
In the system configuration shown in figure 4.5, the optical type CPU link module (ST1) with CPU (A) is
located in the first CPU link position, and link data assignment with CPU (A) is carried out within the first
CPU link area. In addition to this, link data assignment for the CPU (B) optical type CPU link module (ST2)
is also carried out in the first link area when viewed from CPU (A).
As the optical type CPU link module (ST2) with CPU (B) is also in the second CPU link position, link data
assignment with the CPU (B) is carried out in the second link area. Also, link data assignment for the CPU
(A) optical type CPU link module (ST1) is carried out in the second link area when viewed from CPU (B).
CPU(A)
Assignment in CPU(A)
WL0000
WL03FF
WL1000
WL13FF
Second CPU Link module
The area for this module is the second Link area
The area for this module is the first Link area
Figure 4.4 Link area identification
ST1
ST3
ST1
ST2
Figure 4.5 Example of link data assignment
4-3
Chapter 4. Basic CPU Link Operations
First CPU Link module
CPU(B)
Assignment in CPU(B)
WL0000
WL03FF
WL1000
WL13FF
ST2
ST4
ST1
ST2