Programming - Omron NX-series User Manual

4 Serial Communications
4-2-4

Programming

Assign the user-defined variables that are used in the user program on the CPU Unit to the memory
used for CJ-series Units that will be accessed by the NB-series Unit by using AT specification.
Then, create the user program for communicating with the NB-series Unit.
Refer to the NJ/NX-series CPU Unit Software User's Manual (Cat. No. W501) for memory used for
CJ-series Units and AT specification.
Additional Information
The NX1P2 CPU Unit performs programless communications with NB-series Units using the
host link (FINS) protocol.
The host link (FINS) protocol accesses only the memory used for CJ-series Units out of the
entire memory available in the CPU unit based on address specification.
In other words, the CPU Unit uses the memory used for CJ-series Units to communicate data
with NB-series Units.
On the other hand, the NX1P2 CPU Unit uses variables for all processing tasks, for example, to
exchange I/O information with external devices, perform data calculations, and so on.
Therefore, to access memory used for CJ-series Units from the user program on the CPU Unit,
you need to assign user-defined variables to it. This assignment of user-defined variables to
memory used for CJ-series Units is called AT specification.
User program
Data reading,
data calculation,
data transfer, etc.
4 - 8
NX1P2 CPU Unit
User-defined
variables
specification
Variable
specification
Variable
User-defined variables are assigned to
memory addresses with AT specifications.
NX-series NX1P2 CPU Unit Built-in I/O and Option Board User's Manual (W579)
Memory used for
CJ-series Units
AT
CIO
Example 1200.00
AT
Example 1201.00
Host link (FINS)
NB-series Unit
Button
Lamp