Transcript SC 3D - IEC TC 3

Subcommittee 3D
DATA SETS FOR LIBRARIES
SC 3D
Experience report for
implementing IEC 61360 –
Conventions and guidelines
Cape Town, 2005-10-19
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Addie Dijkstra
Secretary, IEC SC3D
SC 3D
Basic contents
IEC 61360 data dictionary at PSC
Need for conventions and guidelines
Conventions for definition
Conventions for naming
Conventions for symbol
Some questions to you
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IEC 61360 data dictionary at PSC
Philips Semiconductors SPIDER program
Type of information to be managed:
Any product information or knowledge
required during any of the stages of the
customer’s product/business creation process
Current status:
Pilot phase – First 700 products defined in the product
library based on data dictionary before end 2005
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Goals
 Capture product parametric information at the
source [and only once]
 Use resulting content to generate:
 Product information web pages and datasheets
 Selection guides
 Electronic data exchange e.g. RosettaNet PIP 2A10
…
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Datasheet
Rapidly growing complexity
 Largest datasheet 1996: 125 pages
 Largest datasheet 2002: 650 pages with 521 device
characteristics!
 Percentage of web visitors downloading datasheets:
87%
 Estimated cost to re-create all existing datasheets at
current rates: EUR XXX,000,000
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Dictionary of data element types
Dictionary and library information model is based on:
 RosettaNet Dictionary Architecture model, compliant
with ISO/IEC information model (IEC 61360-2)
Dictionary content:
 IEC-61360, Philips proprietary and possibly RNTD
Dictionary will be used as (a.o.)
a mechanism to enforce standards and consistency
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Need for conventions and guidelines
Which standards apply
 Information model
 IEC 61360-2
 DET attributes and their definitions
 ISO/IEC 11179-3, IEC 61360-1
 Conventions for writing definitions
 ISO/IEC 11179-4
 Conventions for writing names
 ISO/IEC 11179-5 (includes guidelines for writing
naming conventions and an example convention)
 Conventions for writing symbols
 ISO 31, IEC 60027, 60747, 60748
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Conventions for writing definitions
ISO/IEC 11179-4
A data definition shall [requirements]:
a) be stated in the singular
b) state what the concept is, not only what it is not
c) be stated as a descriptive phrase or sentence(s)
d) contain only commonly understood abbreviations
e) be expressed without embedding definitions of
other data or underlying concepts
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Conventions for writing definitions
ISO/IEC 11179-4
A data definition should [recommendations]:
a) state the essential meaning of the concept
b) be precise and unambiguous
c) be concise
d) be able to stand alone
e) be expressed without embedding rationale,
functional usage, or procedural information
f) avoid circular reasoning
g) use the same terminology and consistent logical
structure for related definitions
h) be appropriate for the type of metadata item
being defined
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Conventions for writing names
ISO/IEC 11179-5
Includes guidelines for writing structured naming
conventions:
 Semantic rules enable meaning to be conveyed;
 Syntactic rules relate components in a consistent,
specified order;
 Lexical (word form and vocabulary) rules reduce
redundancy and increase precision;
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Naming convention for DETs
A data element type name shall:
a) be stated in the singular
b) be written in lower case with the exception of
particular abbreviations and acronyms that are
commonly written in upper case
c) contain only commonly understood
abbreviations and acronyms *
* Managed by a Philips Semiconductors exceptions list for
allowed abbreviations and acronyms
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Specific DET naming rules
Distinguish between type of DET
 Mechanical quantitative data element types
 start with the concept or object being specified followed by
the measured aspect such as: length, height, diameter
 Non-quantitative data element types
 start with the concept or object being specified followed by a
qualifier such as: type, code, name, description
 Electrical quantitative data element types
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Naming convention for DETs
Electrical quantitative data element types
 reflect the electrical symbol in words reading in
reverse order;
 start with the concept or object being specified,
followed by the measured quantity such as:
voltage, current, capacitance, temperature;
 The concept or object is possibly preceded by
one or more qualifiers such as: maximum, peak,
average, total;
 The measured quantity is possibly followed by a
non-quantitative condition such as: from
junction to lead;
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Example
Qualifier
Concept
Measured
quantity
maximum
input
voltage
ambient
temperature
initial
junction
temperature
maximum
repetitive peak
off-state
voltage
transient
thermal
impedance
Non-quantitative
condition
from junction to
lead
REMARK – The allowed non-quantitative conditions are managed in a Philips
Semiconductors non-quantitative conditions list. Only those that are approved
shall be used.
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Conventions for writing symbols
A symbol shall:
a) use a consistent and approved set of
characters;
b) contain only commonly understood
abbreviations;
c) use parentheses “()” to separate adjacent
symbol parts that are written in the same
case (upper or lower);*
d) not exceed a length of 17 characters (not
including mark-up);
* In general, the first part of subscript is not enclosed
in parentheses
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Conventions for writing symbols
A symbol should:
a) be concise - use the minimum number of letters
b) use consistent logical structure for related
symbols
c) reflect the words of the data element type name
reading in reverse order
d) derive the first symbol letter from the measured
quantity (its basic letter symbol) which relates to
the specified unit
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Some questions
Questions:
 What can TC3 apply from what is already
defined in 11179-4 for writing definitions?
 Could TC3 benefit further from joined
conventions on naming and writing
symbols?
 Could IEC benefit from a document such as
a guide on Conventions for naming,
definition and symbols stating the basic
principles?
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Thank you for your attention.