Rockwell Automation 2098-IPD-020-DN Ultra5000 Series Intelligent Positioning Drives with DeviceNet Reference Manual - Manual (Page 22)

Publication 2098-RM002A-EN-P – October 2001
3-2 DeviceNet Overview
Electronic Data Sheet (EDS) files are specially formatted ASCII files
that provide all of the information necessary for a configuration tool
such as RSNetworx for DeviceNet to access and alter the parameters
of a device. Information about each parameter is contained in the file
such as parameter min, max, and default values, parameter data
format and scaling, and the parameter name and units. You can create
or access an EDS file stored in the Ultra5000 Drive with DeviceNet via
RSNetworx for DeviceNet (3.00.01 or later, version 3.00 with Service
Pack 1) or download an EDS file for the Ultra5000 Drive with
DeviceNet from Rockwell Automation/Allen-Bradley web-site
www.ab.com/networks/eds.
DeviceNet Messaging
The Ultra5000 with DeviceNet operates as a slave device on a
DeviceNet network. The drive supports Explicit Messages and Polled
I/O Messages of the predefined master/slave connection set. The
drive also supports the Unconnected Message Manager (UCMM) so
that up to five Group 3 Explicit Message connections may be
established with the drive.
Predefined Master/Slave Connection Set
A set of messaging connections that facilitate communications and is
typically seen in a master/slave relationship is known as the
Predefined Master/Slave Connection set. The master is the device that
gathers and distributes I/O data for the process controller. A
DeviceNet master scans its slave devices based on a scan list it
contains. Each slave device returns I/O data to its master device.
The I/O data exchanged over this connection is pre-defined.
Explicit Response/Request Messages
Explicit Request messages are used to perform operations such as
reading and writing parameter values. Explicit Response messages
indicate the results of the attempt to service an Explicit Request
message.
Polled I/O Command/Response Messages
The Poll Command is an I/O message transmitted by the master
device. A Poll Command is directed toward a specific slave device. A
separate Poll Command must be sent to each slave device that is to be