Hitachi EH-150 Applications Manual page 15

2) Link area identification
(
When two 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 CPU (A) CPU link module (ST1) 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) link module (ST2) is also carried out in the first link
area when viewed from CPU (A).
As the CPU (B) CPU link module (ST2) 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) 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
ST4 ST2
ST1
ST2