Omron CJ Series Operation Manual page 129

User program
Corresponding
device variable
for CJ-series Unit
User-defined
variable
Device Variables for CJ-series Unit
Device variables for CJ-series Units are variables for which AT is specified for the I/O port explained
below. The user program uses device variables for CJ-series Units to access the Configuration for a
unit such as the CJ1W-PRM21.
For allocation of the device variables for CJ-series Unit to the I/O port, refer to How to Create Device
Variables for CJ-series Unit (P. 4-5).
These variables are used to set this Unit and reference statuses from a user program.
Device Variables for CJ-series Unit are positioned internally in the CPU Bus Unit words allocated in
CIO/DM areas shown below.
• CPU Bus Unit words allocated in CIO area (software switches, statuses)
• CPU Bus Unit words allocated in DM area (Reserved for future use)
 I/O Port
An "I/O port" is a logical interface for data exchange by a CPU Unit with a PROFIBUS Master Unit or
other Configuration Unit.
An I/O port has a unique pre-defined name for each unit model and function.
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
CPU Unit
I/O port
CPU Special Unit Words
Allocated in CIO Area
Unit #0
(25 wds)
Unit #15
(25 wds)
CJ Unit Memory
Memory areas such as
CIO and DM
4 Data Exchange with the CPU Unit
Software switches (I/O refresh)
(I/O refresh) status
I/O refresh
I/O refresh
PROFIBUS Master
Unit
4
4-3