Specifications

GLOSSARY
REFERENCE MANUAL 143
Packet A group of bits of fixed maximum size and
well-defined format that is switched and transmitted
as a composite whole through a packet switching
network. Any message that exceeds the maximum
size is partitioned and carried as several packets.
Packet-switched networks Networks of com-
puters or computing devices in which communica-
tion resources are allocated dynamically on a variety
of levels to multiple communicating entities. Messag-
es between entities are partitioned into segments, or
packets, with a fixed maximum size.
Parameter A variable that is usually assigned a
constant value for a specific subroutine, procedure,
or function. Parameters stored in terminal memory or
in the CONFIG.SYS file(s), enable a host or down-
load computer to identify to terminal configuration.
Password A group of characters that identify a
user to the system so that they can gain access to
the system or part of that system. Passwords are
used to ensure the security of computer systems by
regulating the amount of access freedom. The pass-
word used to enter system mode is called the system
mode password
. In the Omni 37xx file system, each
file group (Groups 1–15) also has its own password.
PC Abbreviation for personal computer. Usually, PC
refers to an IBM-compatible personal computer.
Peripheral device In a computer system, any
equipment that provides the processing unit with out-
side communication. Typical peripheral devices for a
POS terminal include PIN pads, bar code wands,
and check readers.
Port An opening or connection that provides electri-
cal or physical access to a system or circuit. Also, a
connection point with associated control circuitry that
allows I/O devices to be connected to the internal
bus of a microprocessor.
POS terminal A terminal used at the point of sale ,
which is usually at a merchant site where a customer
pays for goods or services received. Information
concerning the sale can be entered into the terminal
and transmitted to a remote host computer for verifi-
cation and processing.
Power pack A unit for transforming and converting
electrical power from one AC voltage level to another
AC voltage level, or from AC to DC, for electronic de-
vices.
Prompt A short message, sent from a process to a
user, indicating that the process expects the user to
present fresh data. For example, a prompt appears
on the terminal display asking the user to enter spe-
cific information. See Messages.
Protocol An agreement that governs the proce-
dures used to exchange information between coop-
erating entities. For example, protocols govern the
format and timing of messages exchanged between
devices in a communication system, such as be-
tween a terminal and a host computer.
PTID Permanent terminal ID . An optional identifier
that can be permanently assigned to a VeriFone ter-
minal at the factory, upon customer request. The
PTID has two parts: a 2-digit manufacturer ID (12 for
VeriFone) and a unique 8-digit terminal ID. If no
PTID is assigned, the default PTID value is
1200000000.
Pulse dialing A method of telephone dialing that
specifies a phone number by the number of electrical
pulses sent.