Rockwell Automation 22-COMM-D DeviceNet Adapter - Manual (Page 125)

Glossary
A
Adapter
Devices such as drives, controllers, and computers usually require an
adapter to provide a communication interface between them and a
network such as DeviceNet. An adapter reads data on the network and
transmits it to the connected device. It also reads data in the device and
transmits it to the network.
The 20-COMM-D DeviceNet adapter is an adapter that connects,
PowerFlex drives to a DeviceNet network. Adapters are sometimes also
called “cards,” “embedded communication options,” “gateways,”
“modules,” and “peripherals.”
Automatic Device Replacement (ADR)
A means for replacing a malfunctioning device with a new unit, and
having the device configuration data set automatically. The DeviceNet
scanner is set up for ADR using RSNetWorx. The scanner uploads and
stores a devices configuration. Upon replacing a malfunctioning device
with a new unit (node 63), the scanner automatically downloads the
configuration data and sets the node address.
B
Bus Off
A bus off condition occurs when an abnormal rate of errors is detected
on the Control Area Network (CAN) bus in a device. The bus-off device
cannot receive or transmit messages on the network. This condition is
often caused by corruption of the network data signals due to noise or
data rate mismatch.
C
Change of State (COS) I/O Data Exchange
A device that is configured for Change of State I/O data exchange
transmits data at a specified interval if its data remains unchanged. If its
data changes, the device immediately transmits the change. This type of
exchange can reduce network traffic and save resources since unchanged
data does not need to be transmitted or processed.
Class
A class is defined by the DeviceNet specification as “a set of objects that
all represent the same kind of system component. A class is a
generalization of an object. All objects in a class are identical in form
and behavior, but may contain different attribute values.”