Accessing From The User Program - Omron CJ1W-ECT21 Operation Manual

3 Data Exchange with the CPU Unit
The EtherCAT Slave Unit has two types of I/O ports; one is for the following unit status/slave status
data and the other is for I/O communication area setting and reference tables.
 Unit Status, Slave Status
Unit operating status and error data are allocated with these I/O ports.
 I/O Communication Area Setting and Reference Tables
IN and OUT data area type, starting word, size and setting results are set and referenced with these
I/O ports. The setting data is transferred to the EtherCAT Slave Unit and updated when the Control-
ler is powered ON, the Controller is reset or the EtherCAT Slave Unit is restarted. Refer to the
NJ/NX-series CPU Unit Software User's Manual (Cat. No. W501) for Unit restart methods.
Precautions for Safe Use
Confirm that the I/O Communication Area Setting and Reference Table settings are correct.
Incorrect system settings can cause unexpected behavior.
User-defined Variables
The user program accesses the I/O data that has been allocated with the I/O Communication Area Set-
ting Table via the user-defined variables with an AT specification. User-defined variables are created
using Sysmac Studio.
Have the necessary user-defined variables created before creating a program.
Refer to the Sysmac Studio Version 1 Operation Manual (Cat. No. W504) for details on creating
user-defined variables using Sysmac Studio.
Precautions for Correct Use
The user is responsible for management of the memory used for CJ-series Unit. Please take
great care to avoid overlapping of reference areas between user-defined variables.
3-1-2

Accessing From the User Program

From the user program, various types of information are exchanged using AT specified device variables
for CJ-series Unit that are allocated to the I/O ports, and AT specified user-defined variables that are
allocated to I/O data.
To exchange data, use the data that is listed in the following table in the user program.
Classification of Unit data
Unit Status
Slave Status
I/O Communication Area Set-
ting Table
I/O Communication Area Ref-
erence Table
I/O data
3 - 4
AT specification destination
I/O port
Memory used for CJ-series Unit
CJ-series EtherCAT Slave Units Operation Manual for NJ-series CPU Unit (W542)
Access methods from the user program
Device variable for CJ-series Unit
User-defined variable