Rockwell Automation 25-COMM-D PowerFlex 525 DeviceNet Adapter - Manual (Page 133)

Rockwell Automation Publication 520COM-UM002A-EN-E - April 2013 133
Glossary
Datalinks A Datalink is a type of pointer used by PowerFlex 525 drives to transfer data to
and from the controller. Datalinks allow specified parameter value(s) to be
accessed or changed without using explicit messages. When enabled, each 16-bit
Datalink in a PowerFlex 525 drive consumes 4 bytes in the input image table and/
or 4 bytes in the output image table of the controller.
DeviceNet Network An open producer/consumer Controller Area Network (CAN) which connects
devices (for example, controllers, drives, and motor starters). Both I/O and
explicit messages can be transmitted over the network. A DeviceNet network can
support a maximum of 64 devices. Each device is assigned a unique node address
and transmits data on the network at the same data rate.
A cable is used to connect devices on the network. It contains both the signal and
power wires. Devices can be connected to the network with drop lines, in a
daisychain connection, or a combination of the two.
General information about DeviceNet and the DeviceNet specification are
maintained by the Open DeviceNet Vendor’s Association (ODVA). ODVA is
online at
http://www.odva.org .
EDS (Electronic Data Sheet) Files Simple text files that are used by network configuration tools such as RSNetWorx
for DeviceNet software to describe products so that you can easily commission
them on a network. EDS files describe a product device type and revision. EDS
files for many Allen-Bradley products can be found at
http://www.ab.com/
networks/eds .
Explicit Messaging Explicit messages are used to transfer data that does not require continuous
updates. They are typically used to configure, monitor, and diagnose devices over
the network.
Fault Action A fault action determines how the adapter and connected drive act when a
communications fault (for example, a cable is disconnected) occurs or when the
controller is switched out of run mode. The former uses a communications fault
action, and the latter uses an idle fault action.
Fault Configuration When communications are disrupted (for example, a cable is disconnected), the
adapter and its PowerFlex 525 drive can respond with a user-defined fault
configuration. The user sets the data that is sent to the drive using specific fault
configuration parameters in the adapter. When a fault action parameter is set to
use the fault configuration data and a fault occurs, the data from these parameters
is sent as the Logic Command, Reference, and/or Datalink(s).