Rockwell Automation 1788-FFCT NI-FBUS Configurator User Manual - Manual (Page 11)

Publication 1788-UM052B-EN-P - April 2002
Fieldbus Overview 1-3
Devices
There are three types of devices on a fieldbus network: the link
master, basic devices, and bridges.
• Link master –A link master device controls the communications
traffic on a link. A link master prevents multiple devices from
communicating data at the same time. A link master can be a
Distributed Control System (DCS) or any other device, such as a
valve or a pressure transducer. There can be more than one link
master per link, but only one link master can be the Link Active
Scheduler (LAS) at any given time.
• Basic device –A basic device cannot become the LAS.
• Bridge –A bridge connects two or more links.
Figure 1.2 shows these three types of devices.
Figure 1.2 Fieldbus Network Devices
Identifying Devices
Devices are uniquely identified on the fieldbus network by character
string name, or tag. The device tag is a configurable attribute of the
device that usually describes the type of the device. Device tags are
unique to each device on a fieldbus network.
Another unique identifier of a device is the device ID, which includes
a serial number unique to the device. The device ID is assigned by the
device manufacturer; you cannot configure it.
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