National Instruments NI-DNET - Manual (Page 60)

Appendix A DeviceNet Overview
© National Instruments Corporation A-13 NI-DNET User Manual
As you can see, to use the data bytes contained in I/O messages, it is
important to know the format of a device’s internal input and output
assemblies.
Device Profiles
To provide interoperability for devices of the same type, the DeviceNet
Specification defines various device profiles. The goal behind device
profiles is that for a given type of device, such as a photoelectric sensor, it
should be relatively straightforward to replace a sensor from one vendor
with a sensor from another vendor.
All devices which conform to a given profile must do the following:
• Exhibit the same behavior
• Use the same object model (certain instances are required)
• Contain the same input and output assemblies
• Contain the same set of configurable attributes
In addition to required features, most device profiles define a variety of
optional features. When an optional feature is supported by a vendor, it
must be supported as defined by the DeviceNet Specification. Device
profiles also allow for vendor-specific features.
The DeviceNet Specification provides device profiles for such devices as
photoelectric sensors, limit switches, motor starters, position controllers,
and mass-flow controllers.
Open DeviceNet Vendors Association (ODVA)
This chapter provides only a short summary of DeviceNet. For additional
information, such as a list of DeviceNet products and how to purchase the
DeviceNet Specification, refer to the ODVA Web site at
www.odva.org .