Omron CJ1W-DRM21 Operation Manual page 331

Master COS Send Switch
COS transmission is possible only for User-set allocations using the CX-Integrator.
When required, you can output the remote I/O output data from the master to a specified slave.
In this case, sending output data at the communications cycle timing to the specified slave by other con-
nections selected automatically or by the user (only when using the CX-Integrator) is performed.
In this case, the communications timing is not dependant on the communications cycle time but it is
dependant on the CPU Unit cycle time.
Note When a master or slave sending data with COS communications must handle large quantities of
data or when data is sent frequently using COS communications, the communications cycle time
may actually be longer than when using poll communications. This can have a large impact on
the performance of remote I/O communications and delay responses. Therefore, give ample
consideration to the system performance when using COS.
DeviceNet Units use the Master COS Send Switch in the allocated CIO Area words to execute COS
transmissions from the master to slaves. The procedure is outlined below.
Step 1
Before executing COS transmission, the connection for the destination slave must be set to COS in the
master scan list, using the CX-Integrator.
Step 2
If the bits associated with the node address of *_MstrCOSSendCmd (Master COS Send Switch) or the
array variables
*_MstrCOSSendNdCmd[63] are changed to TRUE, sending OUT data is triggered independently of the
communication cycle.
CPU Unit user program
DeviceNet Unit
Slave
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
associated with the
COS send switch OFF to ON
Communications Communications
cycle time cycle time
I/O using normal connection
node address, *_MstrCOSSendNdCmd[0]
I/O refresh Time
COS send instruction
Communications Communications
cycle time cycle time
COS output
Appendices
to
A-39