Rockwell Automation Allen-Bradley SynchLink 1756-DM Series Design Manual page 104

Glossary 4
Publication 1756-TD008A-EN-P - August 2002
Electronic keying
A system feature which makes sure that the physical module attributes
are consistent with what was configured in the software.
Exact match
An electronic keying protection mode that requires the physical
module and the module configured in the software to match
identically, according to vendor, catalog number, major revision and
minor revision.
End node
A node in SynchLink Star and Daisy chain configurations that only
receives data.
Fiber Optic Cable Segment
A fiber optic cable connecting any two physical devices including
nodes, hubs, and bypass switches. This simplex cable connects the
transmitter of one device with the receiver of another.
Field side
The interface between user field wiring and I/O module.
Hub
A modular, multi-port distribution unit in the star configuration that
consists of a single base block and up to 4 splitter blocks.
Unidirectional data passes through the hub.
Inhibit
A ControlLogix process that allows you to configure a SynchLink
module but prevent it from communicating with the owner controller.
In this case, the controller does not establish a connection.
Insertion Loss
A loss in dB caused by the disruption of light when an object is
inserted in the light path (a connector, bulkhead, splice or cable).
Listen-only connection
An I/O connection that allows a controller to monitor I/O module
data without owning the module.