Rockwell Automation 1794-APB/B FLEX I/O PROFIBUS Adapter Module User Manual - Manual (Page 115)

G–5
Publication 1794ĆUM057B-EN-P - November 2001
LSAP or SAP
Link layer Service Access Point. A logical sub-addresses
within devices that allow the distribution of communication
flow over dedicated tasks, depending on the required
processing. FMS uses LSAPs indifferently to define generic
communication relationships between two devices (logical
communication channels). DP uses predefined LSAPs to
access specific functions or services between masters and
slaves.
master
initiates transfer of messages without any prior remote
request. The right to access the bus (token) is circulated
among the master stations. Management of this logical token
ring is performed automatically by the masters (such as
startup, removal or insertion of masters). Also referred to as
active stations or scanner.
module
any of the plug-in hardware devices that are located in the
1771 I/O chassis: processor, coprocessor, power supply or
I/O module
module slot
location in the I/O chassis for installing a module. Each
module slides into a module slot that lines up with the
backplane connector. Also referred to as slot.
multicast relationships
allow transmission of messages to a group of nodes
simultaneously, but only unconfirmed services are available.
network
a series of stations or nodes connected by some type of
communication medium. A network may consist of a single
link or multiple links.
node
an address or software location on the network. Also referred
to as node.
STATUS LED
a bicolor LED, located on the front panel of the coprocessor
that indicates the condition of the coprocessor
OD
Object Dictionary. In FMS, an OD is a database within the
station, holding the description of all explicit communication
objects of that station and making them available for control
and monitoring.