NonStop S-Series Planning and Configuration Guide (G06.26+)
Glossary
HP NonStop S-Series Planning and Configuration Guide—523303-017
Glossary-81
portable filename character set
portable filename character set. The set of characters that includes the Roman uppercase 
and lowercase letters, the Arabic numerals, the period, the underscore, and the 
hyphen. The hyphen cannot be the first character of a portable filename.
portable pathname character set. The set of characters that includes the Roman 
uppercase and lowercase letters, the Arabic numerals, the period, the underscore, the 
slash (
/), and the hyphen. The hyphen cannot be the first character of a portable 
pathname.
Portable Silicon Operating System (pSOS) system product. A product of Integrated 
Systems Inc. that provides support for industry-standard communications protocols 
based on the UNIX operating system. It is used as a compact multitasking kernel 
operating system for PowerPCs and similar systems.
position ID. A character that indicates the position an HP NonStop™ Cluster Switch 
occupies in a network topology. The position ID is a component of the two-character 
cluster switch name. The cluster switch name includes an external fabric ID (X or Y) as 
the first character and a position ID as the second character. For example, the cluster 
switch name X3 indicates that the cluster switch serves the external ServerNet X fabric 
and occupies position 3 in the topology. Supported values for position IDs are 1 
through 9 or A through Z. Currently supported topologies (star, split-star, and tri-star) 
use position IDs 1, 2, and 3.
position-independent code (PIC). Executable program or library code that is designed to 
be loaded and executed at any virtual memory address, without any modification. 
Addresses that can be modified by the loader do not appear in PIC code, only in data 
that can be modified by the loader. See also dynamic-link library (DLL)
.
POSIX. The Portable Operating System Interface, as defined by the Institute of Electrical 
and Electronics Engineers (IEEE) and the American National Standards Institute 
(ANSI). Each POSIX interface is separately defined in a numbered ANSI/IEEE 
standard or draft standard. The application program interface (API), known as 
POSIX.1, has become ISO/IEC IS 9945-1:1990.
power distribution panel (PDP). A group of panel assemblies that composes a single 
panel that includes buses and overcurrent protection devices (with or without 
switches). A PDP is used for the control of power circuits.
power distribution unit (PDU). An assembly of outlets and fuses that is installed on both 
sides of a modular cabinet. This assembly provides power and over-current protection 
for the components installed in the modular cabinet. 
power domain. A set of customer-replaceable units (CRUs) and field-replaceable units 
(FRUs) that share a set of power rails. For telco Central Office (CO) systems, the 
power domain is the entire system.
power factor. The ratio of real power to apparent power (that is, kilowatts/kilovoltamperes). 
The power factor for a sinusoidal load is determined by the position of the applied 
voltage waveform with respect to the current drawn by the load. When voltage and 










