Omron CJ1W-SCU32 Operation Manual page 84

2 Initial Settings and Allocations of Device Variable for CJ-series Unit
Device variable 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 Unit to access the Configuration Unit such as
Serial Communications Unit.
For allocation of the device variables for CJ-series Unit to the I/O port, refer to How to Create User-
defined Variables (P. 2-13).
I/O port
An "I/O port" is a logical interface for data exchange by a CPU Unit with a Serial Communications
Unit or other Configuration Unit.
An I/O port has a unique pre-defined name for each unit model and function.
An I/O port is automatically created by preparing the Unit Configuration with Sysmac Studio.
For the details of I/O ports defined for the Serial Communications Unit, refer to 2-3 Device Variable
for CJ-series Unit.
There are two types of I/O ports for the Serial Communications Unit: those for Operation Data and
those for System Settings data.
Operation Data
• Software Switch for Each Communications Port
Software switch data to be output (from CPU Unit to this Unit) exists for each communications
port.
Software switch data is stored at the I/O ports for Operation Data allocated for the Serial Commu-
nications Unit.
The user program references data and operates switches via the device variable for CJ-series
Unit.
Data is updated during I/O refreshing.
• Status of Each Communications Port
Status data to be input (from this Unit to CPU Unit) exists for each communications port. Status
data is stored at the I/O ports for Operation Data allocated for the Serial Communications Unit.
The user program references data via the device variable for CJ-series Unit.
Data is updated during I/O refreshing.
System Settings data
• System Settings Data for Each Communications Port
System Settings data exists for each communications port.
Configure the System Settings data using the Edit Special Unit Settings view of Sysmac Studio.
You can also configure System Settings by using the device variables for CJ-series Unit (for sys-
tem setting) that are AT specified to the applicable I/O ports from the user program.
System Settings data is stored at the I/O ports for System Settings data allocated for the Serial
Communications Unit. System Settings data will be retained by the battery even during power
interruptions.
The data is transferred to the Serial Communications Unit and updated when the Controller is
reset, the serial communications port setting is changed, or the Unit is restarted.
2-10 CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)