Pilz PSSnet SHL 8T MRP - Manual (Page 332)

Glossary
332
PSSnet SHL - Command Line Interface
Pilz GmbH & Co. KG, Felix-Wankel-Straße 2, 73760 Ostfildern, Germany
Aging. When an entry for a node is
added to the lookup table of a
switch, it is given a timestamp. Each
time a packet is received from a
node, the timestamp is updated. The
switch has a user-configurable timer
that erases the entry after a certain
length of time with no activity from
that node.
Application Programming
Interface. An API is an interface
used by an programmer to interface
with functions provided by an
application.
AVL tree. Binary tree having the
property that for any node in the
tree, the difference in height
between the left and right subtrees
of that node is no more than 1.
B
BPDU. See “Bridge Protocol Data
Unit” on page 332.
BootP. See “Bootstrap Protocol.”
on page 332.
Bootstrap Protocol. An Internet
protocol that enables a diskless
workstation to discover its own IP
address, the IP address of a BootP
server on the network, and a file to
be loaded into memory to boot the
machine. This enables the
workstation to boot without requiring
a hard or floppy disk drive.
Bridge Protocol Data Unit. BPDU
is the IEEE 802.1D MAC Bridge
Management protocol that is the
standard implementation of STP
(Spanning Tree Protocol). It uses
the STP algorithm to insure that
physical loops in the network
topology do not result in logical
looping of network traffic. Using one
bridge configured as root for
reference, the BPDU switches one
of two bridges forming a network
loop into standby mode, so that only
one side of a potential loop passes
traffic. By examing frequent 802.1d
configuration updates, a bridge in
the standby mode can switch
automatically into the forward mode
if the other bridge forming the loop
fails.
C
Checksum. A simple error-
detection scheme in which each
transmitted message is identified
with a numerical value based on the
number of set bits in the message.
The receiving station then applies a
formula to the message and checks
to make sure the accompanying
numerical value is the same. If not,
the receiver can assume that the
message has been corrupted.
CLI. See “Command Line Interface”
on page 332.
Command Line Interface. CLI is a
line-item interface for configuring
systems.
Complex Programmable Logic
Device. CPLD is a programmable
circuit on which a logic network can