NAiS FP2, Technical Manual

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5-10
Note: Precautions When Allocating Link Areas
If a mistake is made when allocating a link area, be aware that an error will result, and communication
will be disalbed.
Avoid overlapping send areas
When sending data from a send area to the receive area of another FP2/FP2SH/FP
Σ
, there must be a
link relay and link register with the same number in the receive area on the receiving side. In the
example shown below, there is an area between No. 2 and No. 3 which is overlapped, and this will
cause an error, so that communication cannot be carried out.
Example of link relay allocations
System registers
Set value of various control units
No. Name
No. 1 No. 2 No. 3
No. 40 Range of link relays used 64 64 64
No. 42 Starting word no. of link relay send area 0 20 30
No. 43 Size of link relay send area 20 20 34
Invalid allocations
The allocations shown below are not possible, neither for link relays nor for link registers:
- Send area is split
- Send and receive areas are split into multiple segments