Omron NJ101-10 Series, User Manual

Page: 148 / 280

6-1 Process Data Communications (PDO
Communications)
Process data communications cyclically exchanges data between the master and slaves in the proc-
ess data communications cycle (i.e., the task period of primary periodic task or priority-5 periodic task).
From the user program in the NJ/NX-series CPU Unit, slave data is accessed through allocated varia-
bles.
Additional Information
You can use the priority-5 periodic task only with NX701 CPU Units.
6-1-1 Allocated Variables for Process Data Communications
The variables that are allocated depend on the slave type as shown in the following table.
Slave type Allocated variables Operation screen in Sysmac Studio
EtherCAT slaves which are not assigned to axes Device Variables I/O Map
EtherCAT slaves which are assigned to axes Axis Variables Axis Settings
Allocated variables are specified for parameters of instructions in the user program.
Device Variables
The user program in an NJ/NX-series CPU Unit can read and write EtherCAT slave process data that
is not assigned to axes through device variables. (The slave process data is I/O data that is ex-
changed between the master and slaves in each period.)
EtherCAT
Slave
Process data
Device variables
Reading and writing
User program
NJ/NX-series CPU Unit
Slave
Process data
6 Process Data Communications and SDO Communications
6-2
NJ/NX-series CPU Unit Built-in EtherCAT Port User's Manual (W505)