A-1
Appendix A
Appendix A
Detailed DeviceNet Specifications
Data Size and Connection Types
If the connection type can be set when another company’s configurator is being used, select a connection sup-
ported by the DeviceNet Communications Unit.
The following table shows the connection types and data sizes for OMRON DeviceNet Communications Units.
Note The size of the IN/OUT Areas depends on the setting.
DeviceNet I/O communications support the following types of connections.
Model Supported connections Data size (bytes)
Poll Bit strobe Change of
state (COS)
Cyclic IN OUT
E5AR/ER-DRT Yes Yes Yes Yes 0 to 200
(See note.)
0 to 200
(See note.)
Connection type Details Remarks
Poll Used to exchange data between the master and
individual slaves by sending and receiving com-
mands and responses. (Output data is allocated
for commands and input data is allocated for
responses).
---
Bit strobe Used to broadcast commands from the master
and receive input responses from multiple
slaves.
By using one command only, the communica-
tions cycle time is short, but bit strobe connec-
tions can be used only with slaves with 8 or less
input points.
Change of state
(COS)
Normally, input and output data are sent by mas-
ter and slaves at regular cycles, but with a COS
connection, data is sent to the master or slave
when the master or slave data changes.
By setting a long cycle interval, the Network will
not be loaded with communications for minor
data changes, thereby improving the overall effi-
ciency of the Network.
Cyclic Masters and slaves send output or input data at
regular cycles.
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