EN ISO 16284:2001

SLOVENSKI STANDARD
01-maj-2002
2þHVQDRSWLND±,]PHQMDYDLQIRUPDFLM]DRþHVQRRSWLþQRRSUHPR,62
Ophthalmic optics - Information interchange for ophthalmic optical equipment (ISO
16284:2001)
Augenoptik - Datenaustausch zwischen augenoptischen Maschinensystemen (ISO
16284:2001)
Optique ophtalmique - Echange d'informations pour l'équipement d'optique ophtalmique
(ISO 16284:2001)
Ta slovenski standard je istoveten z: EN ISO 16284:2001
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 16284
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2001
ICS 11.040.70
English version
Ophthalmic optics - Information interchange for ophthalmic
optical equipment (ISO 16284:2001)
Optique ophtalmique - Echange d'informations pour Augenoptik - Datenaustausch zwischen augenoptischen
l'équipement d'optique ophtalmique (ISO 16284:2001) Maschinensystemen (ISO 16284:2001)
This European Standard was approved by CEN on 1 June 2001.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16284:2001 E
worldwide for CEN national Members.

Page 2
Foreword
The text of the International Standard ISO 16284:2001 has been prepared by
Technical Committee ISO/TC 172 „Optics and optical instruments“ in collaboration
with Technical Committee CEN/TC 170 „Ophthalmic optics“, the secretariat of which
is held by DIN.
This European Standard shall be given the status of a national standard, either by
publication of an identical text or by endorsement, at the latest by December 2001,
and conflicting national standards shall be withdrawn at the latest by December
2001.
Annex A forms a normative part of EN ISO 16284. Annexes B and C are given for
information only.
According to the CEN/CENELEC Internal Regulations, the national standards
organizations of the following countries are bound to implement this European
Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany,
Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of the International Standard ISO 16284:2001 has been approved by CEN
as a European Standard without any modifications.
NOTE: Normative references to International Standards are listed in Annex ZA
(normative).
Page 3
ANNEX ZA
(normative)
Normative references to international publications with their corresponding
European publications
This European Standard incorporates by dated or undated references, provisions
from other publications. These normative references are cited at the appropriate
places in the text and the publications are listed hereafter. For dated references,
subsequent amendments to or revisions of any of these publications apply to this
European Standard only when incorporated in it by amendment or revision. For
undated references the latest edition of the publication referred to applies (including
amendments).
NOTE Where an International Publication has been modified by common
modifications, indicated by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 13666 1998 Ophthalmic optics – Spectacle lenses - EN ISO 13666 1998
Vocabulary
INTERNATIONAL ISO
STANDARD 16284
First edition
2001-06-01
Ophthalmic optics — Information
interchange for ophthalmic optical
equipment
Optique ophtalmique — Échange d'informations pour l'équipement optique
ophtalmique
Reference number
ISO 16284:2001(E)
©
ISO 2001
ISO 16284:2001(E)
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ii © ISO 2001 – All rights reserved

ISO 16284:2001(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative reference .1
3 Terms and definitions .1
3.1 General.1
3.2 Special characters .2
3.3 Data types.2
3.4 Messages.3
3.5 Records.4
3.6 Sessions .4
3.7 Timeout.5
4 Overview.5
5 Requirements.6
5.1 Records.6
5.2 Reference point records .8
5.3 Generator records.10
5.4 Tracing records.11
5.5 Packets .18
6 Sessions .21
6.1 General.21
6.2 Initialization sessions.21
6.3 Upload sessions .29
6.4 Download sessions .31
7 Other requirements.32
7.1 RS-232 Communications parameters.32
7.2 Operator messages .32
Annex A (normative) Record labels .33
Annex B (informative) Packed binary format example.55
Annex C (informative) CRC calculation.61
ISO 16284:2001(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 16284 was prepared by Technical Committee ISO/TC 172, Optics and optical
instruments, Subcommittee SC 7, Ophthalmic optics and instruments.
Annex A forms a normative part of this International Standard. Annexes B and C are for information only.
iv © ISO 2001 – All rights reserved

ISO 16284:2001(E)
Introduction
This International Standard is the result of a desire shared by manufacturers of optical laboratory equipment and
producers of software used in optical laboratories to simplify the interconnection of their products.
The International Standard defined herein provides:
� a method by which machines and computer systems conduct their exchanges of data;
� a method by which computer systems can initialize such parameters on machines as the manufacturers thereof
allow;
� a method by which machines can initialize computer systems with information that the systems can use for
various purposes;
� a method by which a machine can inform a computer system as to what information it wants to receive, thus
allowing machines to define new interfaces dynamically.
� a standard set of records and device types that are used to communicate agreed-upon sets of information.
The last feature listed above requires that this International Standard be amended on a regular basis, as the need
for new data elements is inevitable.
INTERNATIONAL STANDARD ISO 16284:2001(E)
Ophthalmic optics — Information interchange for ophthalmic
optical equipment
1 Scope
This International Standard establishes a method by which machines and computer software systems used in the
fabrication of ophthalmic lenses can exchange information.
2 Normative reference
The following normative document contains provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent edition of the normative document indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 13666:1998, Ophthalmic optics — Spectacle lenses — Vocabulary.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 13666 and the following
apply.
3.1 General
3.1.1
device
machine or instrument used in the fabrication of ophthalmic lenses that communicates with a computer system to
send or receive job information
3.1.2
host
computer system providing information to or receiving information from a device
3.1.3
job
order for prescription ophthalmic lenses or spectacles
3.1.4
download
communication session in which the host system transmits data to the device
3.1.5
upload
communication session in which the device transmits data to the host
ISO 16284:2001(E)
3.2 Special characters
3.2.1
code separator
special character used to delimit codes in a device record
3.2.2
CRC position character
special character marking the location of the end of the data records and the start of the optional CRC record within
a packet
3.2.3
end character
special character marking the end of a packet
3.2.4
field separator
special character delimiting the fields in a record
3.2.5
label separator
special character separating the record label from the field(s) within a record
3.2.6
mandatory record flag
special character marking certain records as mandatory
3.2.7
start character
special character marking the beginning of a packet
3.2.8
record separators
special characters which delimit records
3.2.9
reserved characters
set of characters reserved for special functions
3.2.10
unknown data indicator
special character indicating that data required for a particular field is unknown to the host
3.2.11
ACK character
special character indicating successful transmission of a packet
3.2.12
NAK character
special character indicating failed transmission of a packet
3.3 Data types
3.3.1
limited data
text data limited to a maximum length
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ISO 16284:2001(E)
3.3.2
literal data
text data limited to a maximum length and specified in this International Standard
3.3.3
numeric data
floating-point and integer numbers
3.3.4
text data
strings of characters that have no pre-defined meaning
3.3.5
integer data
data represented in whole number form
3.3.6
binary data
data presented in a form usable by computer software with little or no translation
NOTE It requires special handling to avoid introduction of control characters.
3.4 Messages
3.4.1
message
structured stream of data transmitted from a host to a device or from a device to a host
3.4.2
confirmation message
message sent by the receiver of a packet and comprised of a single character indicating that the transmission was
successful
3.4.3
positive acknowledgement
single character message indicating successful reception of a sender’s message
3.4.4
negative acknowledgement
single character message indicating unsuccessful reception of a sender’s message
3.4.5
packet
structured message consisting of a start character and a series of records and terminated by an end character
3.4.5.1
data packet
packet sent from a device to a host or a host to a device, and containing requested information
3.4.5.2
request packet
packet sent from a device to a host to initiate a session
3.4.5.3
response packet
packet containing status information
ISO 16284:2001(E)
3.5 Records
3.5.1
record
structured stream of characters including a record label, a label separator, zero or more data fields separated by
field separators and a terminating record separator
3.5.2
data field
single data element within a record
3.5.3
record label
means of identifying data contained in a record, limited in length to 8 characters and not including special
characters defined in this International Standard
3.5.4
ASCII record
record comprised of ASCII characters and conforming to the structures defined herein
3.5.5
binary record
record comprised of bytes encoded using the binary number system
3.5.6
chiral record
record with two fields, one for a data element for a right lens or eye, and one for a left, arranged in the order right
then left
3.5.7
CRC record
record at the end of any packet containing a CCITT CRC-16 cyclical redundancy check value calculated on the
characters transmitted
3.5.8
device record
record containing job specific data elements conveyed between devices and hosts
3.5.9
interface record
record supporting the operation of the host-device interface and not containing job-specific data
3.6 Sessions
3.6.1
session
sequence of messages passed between a device and a host that serves to exchange information related to a
single order or task
3.6.2
initialization session
specialized session allowing devices to provide hosts with information that would otherwise be included with each
request, such as machine model, software version and operator ID
3.6.2.1
auto-format initialization
initialization session allowing devices to define sets of device records to be requested from hosts
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ISO 16284:2001(E)
3.6.2.2
preset initialization
initialization session allowing devices to transmit sets of identifying data to hosts
3.6.3
download session
session in which information is passed from a host to a device
3.6.4
upload session
session in which information is passed from a device to a host
3.6.5
INFO session
upload request packet containing job status information used to indicate the completion of a job by a device
3.6.6
MNT session
upload request packet containing vendor specific device information
3.7 Timeout
3.7.1
timeout
numeric value representing that period of time that a host or device shall wait for the arrival of data, after which it
assumes that such data will not be forthcoming
3.7.1.1
confirmation timeout
timeout which applies to the reception of the confirmation message
3.7.1.2
intercharacter timeout
timeout which applies to the interval between successive characters in a stream of data
3.7.1.3
packet timeout
timeout which applies to the reception of a packet
4Overview
The strategy used in this International Standard for the exchange of data between devices and hosts can be
expressed as follows.
A machine used in the fabrication of ophthalmic lenses (a device) sends a request to a computer system (a host),
indicating a need to do one of the following:
� initialize information to identify the device, software versions, model numbers, etc.;
� upload to the host, information for it to store and/or use in the processing of ophthalmic prescription orders;
� download from the host, information required by the device for it to perform its tasks.
Communication can be initialized in two ways. The device may begin an initialization session or the host can force
the device to do so by refusing to accept a normal request and asking for initialization via a special error response.
For upload requests, the host acknowledges the request and the device sends its data, the receipt of which the
host acknowledges. For download requests, the host responds to the request with the data requested.
ISO 16284:2001(E)
The variable-length packets of data that comprise this exchange consist of a series of records, each of which
contains data and a label identifying the data. This International Standard defines a set of labels and characterizes
the data associated with each. This set of labels shall be expanded as needed in the future.
An exchange of packets related to a single job is called a session. The structure of these sessions and the packets
of records of which they are comprised is the substance of this International Standard.
Although this International Standard was conceived as being implemented on point-to-point RS-232 serial links, it
could be implemented on other hardware platforms. As this is done, specifications shall be incorporated into this
International Standard so as to maximize interconnectability amongst diverse hosts and devices.
5 Requirements
NOTE In the examples in this International Standard, in the interests of legibility, the RECORD SEPARATORS may be
omitted, the START CHARACTER may be placed on a separate line and CRC RECORDS may be excluded. Remarks have
been included as REM records. Comments are enclosed in square brackets ( [ … ] ) and are not part of the data stream.
Ellipses ( "…" ) are used to indicate more data of the same type as precedes and follows the ellipses. SPACES have been
inserted around record and field separators for readability; in practice these should not be included in packets as this needlessly
decreases the efficiency of expression. In the descriptions below, REQUEST, RESPONSE and DATA refer to packets.
5.1 Records
5.1.1 Interface records
This International Standard defines a set of interface records. These records contain information which the host
and device use to communicate. They do not contain job-specific data. These are enumerated in A.2.
5.1.2 Device records
This International Standard defines a set of device records which identify the data elements that might be required
by any of the devices that in turn might be required for the fabrication of a job. These records are enumerated in
A.1.
5.1.3 Preset device types
This International Standard further identifies subsets of device records that are deemed to be appropriate for
specific types of devices. These are enumerated in A.3.
5.1.4 Mandatory records
Records that are mandatory are so designated in their definitions. Records not so designated may be presumed to
be optional.
5.1.5 Records with unknown values
If the host is requested to send any mandatory record for which it has no information, it shall send the record with a
question mark "?" in all the unknown data fields in order to indicate that the information is not available. Such
records shall be properly formatted according to the rules for chiral records.
5.1.6 Ignored records
Whenever a host receives a record with a label it does not recognize, it shall ignore the record.
6 © ISO 2001 – All rights reserved

ISO 16284:2001(E)
5.1.7 Experimental records
When a machine vendor wishes to test new records prior to submitting them for inclusion in this International
Standard, such records should use labels that begin with an underscore character (ASCII "_", decimal 95). Record
labels are limited in length to 8 characters and may not include special characters defined in this International
Standard.
5.1.8 Reserved characters
5.1.8.1 Control characters and the additional characters specified may not appear in transmitted data stream
except as specified. The set of reserved characters is specified in Table 1.
5.1.8.2 Reserved characters shall appear in ASCII records only to provide the functionality that they are
assigned, as in the case of record and field separators. Reserved characters which conform to the definition of text
data may also appear in text fields, which are delimited by double quote characters.
5.1.8.3 When a reserved character with a decimal value less than 32 appears in a binary record, it shall be
"escaped" in the following manner. In place of such a character, two characters shall be sent. The first character
shall be an ESC character followed by the original character with its high bit set, i.e., the character is OR’dwith
decimal 128, hex 0�80. The receiver, on receipt of an ESC character, shall discard the ESC character and clear the
high bit of the following character. The CRC value, if present, shall be determined after such reserved characters
are escaped, so that a receiver need not process packets prior to validating a received packet’s CRC.
NOTE In other words, the transmitter encodes control characters before calculating the CRC, and the receiver calculates
the CRC before decoding them.
EXAMPLE A stream of bytes (a short tracing record in absolute binary form) before and after having been "escaped" as
described above.
Before:
R=175 9 23 10 45 10 223 9 90 9 205 8 89 8 252 7 183 7 143 7
130 7147 7197 724813681891679391085101910
213 9 146 9 75 9 14 9 199 8 120 8 38 8 222 7 166 7 131 7
117 7 122 7 149 7 191 7 241 7 41 8 92 8 152 8 229 8 67 9
After:
R=175 9 23 27 138 45 27 138 223 9 90 9 205 8 89 8 252 7 183 7 143 7
130 71477197 72481368189167939 27 138 85 27 138 27 147 27 138
213 9 146 9 75 9 14 9 199 8 120 8 38 8 222 7 166 7 131 7
117 7 122 7 149 7 191 7 241 7 41 8 92 8 152 8 229 8 67 9
5.1.8.4 Limited data is a string of ASCII characters in the range 32 to 127 decimal. The length is limited to
12 characters. Limited data shall be enclosed in double quotation marks (ASCII 34 decimal). Limited data shall not
contain quotation marks.
5.1.8.5 Text data is a string of ASCII characters in the range 32 to 127 decimal having no predefined meaning.
Length is limited to 80 characters. Text data shall be enclosed in double quotation marks (ASCII 34 decimal). Text
data shall not contain quotation marks.
5.1.8.6 Literal data is a string of characters whose meaning is implied by the record type and specified in this
International Standard. Length is limited to 12 characters unless otherwise noted in the record definition. Literal
data shall not contain special characters defined by the interface. No double quotation marks are needed.
ISO 16284:2001(E)
Table 1 — Reserved characters
Hexadecimal Decimal Control
Character Use
Value Value Key
FS 0�1C 28 ^\ Start of message
GS 0�1D 29 ^] End of message
DC1 0�11 17 ^Q Reserved (XOFF)
DC3 19 ^S Reserved (XON)
0�13
ACK 0�06 06 ^F Positive acknowledgement
NAK 0�15 21 ^U Negative acknowledgment
ESC 0�1B 27 ^[ Escape
RS 0�1E 30 ^^ CRC separator
SUB 0�1A 26 ^Z DOS End-of-file marker
CR 0�0D 13 ^M Record separator
LF 0�0A 10 ^J Record separator
; 0�3B 59 ; Field separator
= 61 = Label separator
0�3D
@ 0�40 64 @ Reserved
, 0�2C 44 , Code separator
* 0�2A 42 * Mandatory record flag
? 0�3F 63 ? Unknown data indicator
5.2 Reference point records
5.2.1 Records are defined to indicate the horizontal and vertical distances between two reference points or to
indicate an action that a machine should take relative to a reference point. The following naming scheme will clarify
all such reference records included in this International Standard and can easily be extended for future ones.
5.2.2 The first two letters of the record label describe the first reference point, the second two letters of the
record label describe the second reference point and the last two letters indicate "IN" (horizontal) or "UP" (vertical)
directions. The values indicate the position of the second reference point with respect to the first reference point.
5.2.3 A positive IN value indicates that the second reference point is towards the nasal relative to the first.
5.2.4 A negative IN value indicates that the second reference point is towards the temporal relative to the first.
5.2.5 A positive UP value indicates that the second reference point is above the first.
5.2.6 A negative UP value indicates that the second reference point is below the first.
8 © ISO 2001 – All rights reserved

ISO 16284:2001(E)
Table 2 — Reference point identifiers
Identifier Reference point
BC Blank centre
FB Finish block
FC Frame centre
OC Optical centre/Prism reference point
SB Surface block
SG Segment
Table 3 — Reference point records
Label Meaning
FBFCIN, FBFCUP Finish block to frame centre
FBSGIN, FBSGUP Finish block to segment
FBOCIN, FBOCUP Finish block to prism reference point (O.C.)
SBBCIN, SBBCUP Surface block to blank centre
BCSGIN, BCSGUP Blank centre to segment
BCOCIN, BCOCUP Blank centre to optical centre
SBSGIN, SBSGUP Surface block to segment
SBOCIN, SBOCUP Surface block to prism reference point
SBFCIN, SBFCUP Surface block to frame centre
SGOCIN/SGOCUP Segment to O.C.
FCSGIN/FCSGUP Frame centre to segment (similar to segment height or drop)
FCOCIN/FCOCUP Frame centre to O.C. (similar to O.C. height or drop)
ISO 16284:2001(E)
5.3 Generator records
5.3.1 The surface generator interface includes a number of records used to indicate adjustments that should be
applied to the generator machine settings. Because this International Standard provides for a complete data set
("preset packet") to be sent to an "unknown" generator, it is necessary to clarify some of the relationships amongst
these records, especially as relates to the "compensation" fields.
The position of a lens in a generator can be determined by the RNGH, RNGD, SAGRD and SAGBD fields (ring
height, ring diameter, lens sag at ring diameter and lens sag at blank diameter, respectively). Some generators,
especially those with exclusively mechanical components, may presume certain values for some of the above
records and may be unable to effect the adjustments required by the mismatch in assumptions. The following
compensation fields provide the data required to make these adjustments.
5.3.2 BLKCMP represents the change that is required to be made to the generator thickness setting that arises
from a mismatch between the curvature of a block that has a curved contact surface with the lens and the curvature
of the lens blocked thereon. The BLKB field contains the curvature of that surface of the block that contacts the
lens; the BLKD field contains the diameter of the block.
5.3.3 When the blocks used for a job do not have a curved contact surface, the BLKB field is not necessary. If it
is sent in such a case, its value should be equivalent to IFRNT.
5.3.4 RNGCMP represents the change that is required to be made to the generator thickness setting that arises
from a mismatch between the blocking ring height and/or diameter, known to the host, and that which is presumed
by the generator.
5.3.5 FINCMP indicates the amount of thickness that should be added to the generator setting to allow for
material removed during fining (smoothing) and polishing.
5.3.6 THKCMP shall be used for such compensations to thickness as may be required, which are not otherwise
handled by the records defined in this International Standard.
NOTE The above-enumerated thickness compensation fields apply equally to GTHK and OTHK.
5.3.7 EECMP indicates a dioptre amount that shall be added to the GCROS and GCROSX values when elliptical
error compensation is required.
5.3.8 A host can maintain complete control over the settings on a generator by including all of the compensation
values that it believes to be required by a particular machine in the basic setting records and sending zero values in
the compensation records; e.g., sum GCROS with EECMP, send the result as GCROS and send EECMP with
values equal to zero.
5.3.9 In compensation records, zero values indicate that the host does not want the machine to apply any
compensation that it may be capable of being set to do.
5.3.10 The ABSENCE of compensation fields indicates that the generator should apply such compensations as
it may be set to do.
5.3.11 Prism versus decentration: the fields GPRVM and GPRVA represent prism magnitude and direction to
be generated. These values shall include all possible contributions to prism, including Rx prism, thinning prism, and
prism for decentration. The fields SBOCIN and SBOCUP express vector distances to which the grinding centre is to
be offset from the surface block centre, laterally and vertically. In order that both be expressed in a single packet,
as would be desirable in the case of a "generic" GEN request, a set of prism records is defined, RPRVM and
RPRVA, which represents prism to be ground exclusive of the decentration expressed in SBOCIN/SBOCUP. In
addition, when decentration is expressed directly (via SBOCIN/SBOCUP), the OTHK value should be present. The
following rules describe how these fields should be aggregated.
5.3.11.1 When expressing decentration to be generated as prism, the following fields are used together:
GPRVM, GPRVA and GTHK.
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ISO 16284:2001(E)
5.3.11.2 When expressing decentration to be generated directly, the following fields are used together: RPRVM,
RPRVA, SBOCIN, SBOCUP and OTHK.
5.3.11.3 Because the method described in 5.3.11.1, in which decentration is expressed in the form of prism, is
the more universal one for expressing decentration to be ground, the set of records described therein should be
supported by all generators and hosts. The set of records described in 5.3.11.2, in which decentration is expressed
as vectors, should be included in addition to the 5.3.11.1 set. Generators not supporting the vector method can
safely ignore the vector fields.
5.3.12 Pad thickness: the inclusion of the PADTHK record indicates that LAP curves cut by a generator should
be compensated for the thickness of the pad. No compensation should be made to the lens curves expressed in
GBASE/GCROS or GBASEX/GCROSX. It is the responsibility of the host to determine such compensations as
shall be applied to generator curves, the need for which may result from the use of laps not compensated for pad
thickness, or the desire to fine lenses from edge to centre.
5.3.13 Curve signs: concave curves shall be expressed as negative numbers and convex curves as positive
numbers. One implication of this is that for generators that cut laps, the lens curves and lap curves shall have
opposite signs.
5.4 Tracing records
5.4.1 Expression of trace data
This begins with a TRCFMT record, which specifies the format in which the tracing is to be expressed, the number
of points to be transmitted, whether the radii are equiangular, the orientation of the tracing and an indication of what
was traced.
5.4.2 Radius data
These are contained in "R" records. Sag data is contained in "Z" records. Angle data for radius data is contained in
"A" records and for sag data in ZA records. For the ASCII format, all of the records follow the 80-character line limit
rule, therefore there may (in fact, will likely) be multiple R, A, Z and ZA records for each tracing. For BINARY data,
the line limit rule will not apply and there will be only one R, A, Z and ZA record as needed. Radius and sag data is
expressed in hundredths of a degree with an implied decimal point.
EXAMPLE Radius data:
a) ASCII format
TRCFMT=1;400;E;R;F
R=2479;2583;2605;2527;2394;2253;2137;2044;1975;1935
R=1922;1939;1989;2072;2184;2322;2471;2599;2645;2579
etc…
b) Binary formats
TRCFMT=2;400;E;R;F
R=
5.4.3 Uneven angles
When these are specified in the TRCFMT record, angle data is required. It shall appear immediately after its
corresponding radius data. Angle data is contained in one or more "A" records, and shall be expressed in the same
format as the radius data to which it corresponds. Angle data is expressed hundredths of a degree with an implied
decimal point and shall be in the range 0-35999.
NOTE Angle data may also follow the sag data if uneven angles are specified for the sag data.
ISO 16284:2001(E)
5.4.4 ZFMT
The sag data format record, ZFMT, has exactly the same definition as the TRCFMT record. The same rules apply
to angle data for sag data as to angle data for radius data.
5.4.5 "R" records
These shall appear immediately after the TRCFMT record. All of the "R" records for a tracing (i.e., a single side,
when two are provided) appear together. Each side has its own TRCFMT record.
5.4.6 "Z" records
These shall appear immediately after the ZFMT record. All of the "Z" records for a tracing (i.e., a single side, when
two are provided) appear together. Each side has its own ZFMT record.
5.4.7 "A" or ZA records
These, when present, shall appear immediately after their corresponding set of "R" or "Z" records. ZFMT and "Z"
records shall appear immediately after their corresponding TRCFMT and "R" records.
EXAMPLE A two-eye tracing data set (abbreviated) showing the required sequence of records
TRCFMT=1;400;U;R;F
R=2479;2583;2605;2527;2394;2253;2137;2044;1975;1935
R=1922;1939;1989;2072;2184;2322;2471;2599;2645;2579
…
R=1909;1914;1941;1983;2033;2089;2140;2200;2277;2371
A=0;90;180;270;360;450;540;630;720;810
A=900;990;1080;1170;1260;1350;1440;1530;1620;1710
…
A=35100;35190;35280;35370;35460;35550;35640;35730;35820;35910
ZFMT=1;100;U;R;F
Z=322;331;342;328;314;308;300;295;288;280
…
Z=316;318;324;328;333;343;349;352;357;362
ZA=0;360;720;1080;1440;1800;2160;2520;2880;3240
…
ZA=32400;32760;33120;33480;33840;34200;34560;34920;35280;35640
TRCFMT=1;400;U;L;F
R=2517;2450;2379;2318;2247;2168;2086;2014;1958;1923
R=1909;1914;1941;1983;2033;2089;2140;2200;2277;2371
…
R=1922;1939;1989;2072;2184;2322;2471;2599;2645;2579
A=0;90;180;270;360;450;540;630;720;810
A=900;990;1080;1170;1260;1350;1440;1530;1620;1710
…
A=35100;35190;35280;35370;35460;35550;35640;35730;35820;35910
ZFMT=1;100;U;R;F
Z=322;331;342;328;314;308;300;295;288;280
…
Z=316;318;324;328;333;343;349;352;357;362
ZA=0;360;720;1080;1440;1800;2160;2520;2880;3240
…
ZA=32400;32760;33120;33480;33840;34200;34560;34920;35280;35640
12 © ISO 2001 – All rights reserved

ISO 16284:2001(E)
5.4.8 Frame tracings
These shall be centred geometrically when presented to the host. The host may decentre the shape in order to
produce a certain effect on a device.
5.4.9 Tracing data
These shall be expressed so that the first radius is at zero degrees (3 o’clock on standard polar scale) and shall
proceed anti-clockwise. When angle data are provided, the starting radius shall be the one at the first available
meridian greater than or equal to zero.
5.4.10 Eye orientation
5.4.10.1 Eye orientation, right or left, shall be viewed as a refractionist views a spectacle wearer; right-eye
oriented data therefore start at the nasal side while left-eye data start at the temporal.
5.4.10.2 Eye orientation may be established during initialization. If it is not, it is specified in the tracer’s request
packet.
5.4.10.3 When eye R (right) is specified, the device wants to send or receive a single set of trace data with
right-eye orientation.
5.4.10.4 When eye L (left) is specified, the device wants to send or receive a single set of trace data with left-
eye orientation.
5.4.10.5 When eye B (both) is specified, the device wants to send or receive both right and left sets of tracing
data, each in the appropriate orientation.
5.4.11 Eye orientation during tracing transmission
5.4.11.1 When eye R (right) is specified in the TRCFMT or ZFMT records, the tracing will have RIGHT eye
orientation.
5.4.11.2 When eye L (left) is specified in the TRCFMT or ZFMT records, the tracing will have LEFT eye
orientation.
5.4.11.3 B shall not be specified in data packets, only in request or initialization packets. In data packets in
which both sides are included, there shall be two TRCFMT records, one for each side, labeled appropriately.
5.4.12 Hosts and devices
These shall handle the reception of either orientation of tracing data without generating an error condition.
5.4.13 Tracing format example data
In the expression of sag data, the smallest number in the data set shall be positive and shall represent the point
located furthest toward the front of the frame or lens. The distance from this point to other points in the data set
shall have positive values in increments of 0,01 mm.
NOTE 1 It is strongly recommended that devices be consistent in the representations of data. While it is not expressly
forbidden, representing radius data in one orientation and sag data in another, might violate host systems’ programmers
unwarranted assumptions and fail.
NOTE 2 The following small sample tracing, comprised of 40 radii, is used for the examples below. The sample is not
formatted in any particular way; it is just a list of the radius values used in the examples that follow.
24.79, 25.83, 26.05, 25.27, 23.94, 22.53, 21.37, 20.44, 19.75, 19.35,
19.22, 19.39, 19.89, 20.72, 21.84, 23.22, 24.71, 25.99, 26.45, 25.79,
ISO 16284:2001(E)
25.17, 24.50, 23.79, 23.18, 22.47, 21.68, 20.86, 20.14, 19.58, 19.23,
19.09, 19.14, 19.41, 19.83, 20.33, 20.89, 21.40, 22.00, 22.77, 23.71
5.4.14 ASCII absolute format
In this format, each radius is presented as a 4-digit decimal number in hundredths of a millimetre with an
...