Remote I/O Slave Communications; Slave Remote I/O Communications; Allocation Methods - Omron CJ1W-DRM21 Operation Manual

5 Remote I/O Slave Communications

5-1

Slave Remote I/O Communications

A CJ-series DeviceNet Unit can function as a Slave Unit in remote I/O communications and a single CJ-
series DeviceNet Unit can function as both a Master Unit and a Slave Unit. This section describes Slave
communications.
Slave Communications
CJ-series DeviceNet Unit (Master)
CJ-series CPU Unit
• In the following descriptions, the areas used to transfer data from the master to the slaves are
called OUT areas and the areas used to transfer data from the slaves to the master are called the
IN areas.
• In the following descriptions, a CJ-series DeviceNet Unit set to function as a master is referred to
as a "Master Unit" and a CJ-series DeviceNet Unit set to function as a slave is referred to as a
"Slave Unit".
5-1-1

Allocation Methods

The specified areas in the memory used for CJ-series Unit of the NJ-series CPU Unit in which a Slave
Unit is installed, are allocated to the Master Unit as DeviceNet slave. They are allocated using one of
the following methods:
1) Fixed allocations
2) User-set allocations
To access the OUT/IN Areas that was specified with the above method from the user program, a
user-defined variable that specifies the AT specification of that area needs to be defined.
5-2
Remote I/O communications
DeviceNet
NJ-series CPU Unit
CJ-series DeviceNet Unit (Slave)
Slaves
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
IN area OUT area
IN area OUT area