User's Manual

Bridges Hardware Guide Silver Spring Networks 32
Glossary
path Refers to how cells, nodes, and endpoints are
connected together. For example, the path from cell
A to endpoint Z runs through node B. See also
route.
path loss Total amount of power lost in the propaga-
tion of the RF signal from the transmitter to the re-
ceiver.
payload The payload is that part of a packet that is
not the header. Payloads consist of application data
such as interval read results. In the case of an On
Demand ping, the user can set the payload size to
increase or decrease the size of the packet. In RF
networks, small packets can traverse the network
more successfully than larger packets. When per-
forming an On Demand ping, you can configure the
payload up to 255 bytes. See also packet and ping.
peak demand The maximum level of use by custom-
ers of a system during a specified period.
peaking capacity Capacity of generating equipment
normally reserved for operation during the hours of
highest daily, weekly, or seasonal loads.
peaking plant A power plant that normally operates
only during peak load periods.
percentile Similar to the meaning of median, the per-
centile is a value within a range of values at which
the percentage of the values lie at or below the ex-
pressed percentile. For example, 25% of the values
lie at or below the 25th percentile, which implies that
75% of the values lie at or above the 25th percen-
tile. Similarly, 75% of the values lie at or below the
75th percentile. The median can also be expressed
as the 50th percentile.
ping Packet InterNet Groper or Packet InterNet Go-
pher. A program to test the reachability of devices
on a network. The ping program sends a packet to
the named device and returns data indicating how
long, in milliseconds, the packet took to reach the
device and return (also known as round trip time).
See also On Demand, packet, reachable, and trac-
eroute.
port In networking, a port is used in conjunction with
a computer address and specifies a process run-
ning on the destination computer.
potential transformer A step-down transformer
used to scale down very high voltages to levels that
are safer for instrument operation. For example,
600:1 scale factors are not uncommon with poten-
tial transformers. A common device in substations.
power out message See last gasp.
preferred Access Point See primary Access Point.
primary Access Point The best performing, most re-
liable Access Point as determined by the endpoint
device. See also secondary Access Point.
protocol An agreed upon format for transmitting data
between two devices. Protocols have rules that
govern the syntax, semantics, and synchronization
of communication. Protocols may be implemented
by hardware, software, or a combination of both.
Q
queue A list. In AMM, a list of meters associated with
a schedule is referred to as a queue. In general
computing, a queue can be a list of commands to
execute one by one. See also requeue.
R
rate structure The various rates charged by a utility
for its services.
RDBMS Relational Database Management System,
such as Oracle.
reactor High-voltage inductors used as a shunt to
regulate transmission voltage and to reduce fault
current in transmission lines. An example of an RTU
device.
read (meter read) The collection of usage data from
a meter. Collections of meter reads are referred to
as read data.
reachable The ability to send and receive data to and
from a meter. A reachable meter is usually read-
able. However, a meter may be reachable with
small packet sizes, but may not be readable with
the larger packet sizes necessary for a successful
read.
recloser Similar to a circuit breaker, a recloser is
equipped with a mechanism to automatically close
the breaker after it has opened due to a temporary
electrical fault. An example of an RTU device.
relay A device on a network used to extend the reach
of a network. Relays are typically placed high for