I
50
Model 6276 User Guide
B • Glossary of terms
I
IDE
Integrated Drive Electronics—a hard disk drive stan-
dard interface for PCs.
IEC
International Electrotechnical Committee
IEEE
Institute of Electrical and Electronics Engineers
IN/C
Insulation No Connect—required for safety agency
insulation requirements.
ISA
Industry Standard Architecture—A specification by
which Personal Computers (PCs) add boards.
K
Keying
A mechanical means of polarizing connectors in order
to prevent similar connectors from being mated. This
is necessary when 2 or more similar connectors must
be connected to a backplane which requires that the
board being connected is unique for a particular slot.
N
N+1 Redundant
An environment containing more than two power
supplies, where the power supplies typically current
share, with fault tolerance such that one power supply
may fail and the system will continue to operate.
NEBS
Network Equipment Building Standards—Defines a
rigid and extensive set of performance, quality, envi-
ronmental and safety requirements developed by
Bellcore, the R&D and standards organization owned
by the seven regional Bell operating companies
(RBOC’s).
NP
Not Populated—pins within connector that must not
be populated due to safety requirements.
P
PCI
Peripheral Component Interconnect. A specification
for defining between logic components. Typically
used for interconnecting high-speed, PC-compatible
chipset components. The PCI specification is issued
through the PCI Special Interest Group (PCI SIG).
PCI SIG
Peripheral Component Interconnect Special Interest
Group
PICMG
PCI Industrial Computers Manufacturers Group—a
consortium of industrial computer product vendors
who develop specifications for PCI-based systems and
boards for use in industrial computing applications.
Platform
Describes the system environment, including the
backplane and related enclosure.
S
SELV
Safety Extra Low Voltage—a term generally defined
by the regulatory agencies as the highest voltage that
can be contacted by a person and not cause injury. It
is often specifically defined as 30 VAC or 42.4 VDC.
S-HAZ
Secondary Hazardous—any voltage within a system
that is greater than 60VDC (42.4VAC-peak), NOT
meeting the requirements for a LIMITED CUR-
RENT CIRCUIT, or for a TNV CIRCUIT. Typical
ringing voltage is considered SECONDARY HAZ-
ARDOUS unless it is current limited. Raw ringing is
considered SECONDARY HAZARDOUS. (Refer to
IEC950 or PICMG 2.5 R1.0 CompactPCI‚ Com-
puter Telephony Specification for information.)