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A-39
Appendices
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
A-2 De
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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 associated with the node address,
*_MstrCOSSendNdCmd[0]
to
*_MstrCOSSendNdCmd[63]
are changed to TRUE, sending OUT data is triggered independently of the
communication cycle.
CPU Unit user program
DeviceNet Unit
Slave
COS send switch OFF to ON
I/O refresh
Time
COS send instruction
I/O using normal connection
COS output
Communications
cycle time
Communications
cycle time
Communications
cycle time
Communications
cycle time
Summary of Contents for CJ1W-DRM21
Page 12: ...Manual Structure 10 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Page 42: ...Revision History 40 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 ...
Page 345: ...Index 1 CJ series DeviceNet Units Operation Manual for NJ series CPU Unit W497 I Index ...
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