Lossary – Rockwell Automation DeviceNet Communications Module User Manual

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Glossary

Glossary-1

LOSSARY

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
device’s configuration. Upon replacing a malfunctioning device with
a new unit (node 63), the scanner automatically downloads the
configuration data and sets the node address.

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.

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 - As defined by the DeviceNet specification, “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.”

controller - Also called programmable logic controller. A solid-state
control system that has a user-programmable memory for storage
of instructions to implement specific functions such as I/O control,
logic, timing, counting, report generation, communication,
arithmetic, and data file manipulation. A controller consists of a
central processor, input/output interface, and memory.