IEC 62055-51:2007

INTERNATIONAL IEC
STANDARD 62055-51
First edition
2007-05
Electricity metering – Payment systems –
Part 51:
Standard transfer specification (STS) –
Physical layer protocol for one-way numeric
and magnetic card token carriers

Reference number
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INTERNATIONAL IEC
STANDARD 62055-51
First edition
2007-05
Electricity metering – Payment systems –
Part 51:
Standard transfer specification (STS) –
Physical layer protocol for one-way numeric
and magnetic card token carriers

PRICE CODE
Commission Electrotechnique Internationale S
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – 62055-51 © IEC:2007(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5

1 Scope.6
2 Normative references .6
3 Terms, definitions and abbreviations .7
3.1 Terms and definitions .7
3.2 Abbreviations .7
3.3 Notation and terminology.8
3.4 Numbering conventions .8
4 STS protocol reference model .9
5 POSToTokenCarrierInterface: Physical layer protocol .10
5.1 TCDU .10
5.2 Magnetic card token carrier .11
5.3 Numeric token carrier .15
6 TokenCarrierToMeterInterface: Physical layer protocol.17
6.1 TCDU .17
6.2 Magnetic card token carrier .17
6.3 Numeric token carrier .18

Annex A (informative) Procurement options for users of STS-compliant systems .20

Bibliography.21

Table 1 – Data elements in the TCDU .10
Table 2 – Data elements in the IDRecord.10
Table 3 – Mandatory data fields for Record1 to be encoded on Track 3 .13
Table 4 – Separator data field to be encoded on Track 3 with optional Record2.13
Table 5 – Data fields for optional Record2 to be encoded on Track 3.13
Table 6 – Example of 66-bit binary to 20-digit decimal conversion .16
Table 7 – Data elements in the TCDU .17
Table 8 – Example of a 20-digit decimal to 66-bit binary conversion .19
Table A.1 – Items that should be noted in purchase orders and tenders.20

Figure 1 – Physical layers of the STS protocol stack.9

62055-51 © IEC:2007(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
METERING – PAYMENT SYSTEMS –
Part 51: Standard transfer specification (STS) –
Physical layer protocol for one-way numeric
and magnetic card token carriers

FOREWORD
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all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
The International Electrotechnical Commission draws attention to the fact that it is claimed that compliance with
this document may involve the use of patents concerning the numeric token carrier given in 5.3 and 6.3.
The IEC takes no position concerning the evidence, validity and scope of these patent rights. The holder of these
patent rights has assured the IEC that he is willing to negotiate licences under reasonable and non-discriminatory
terms and conditions with applicants throughout the world. In this respect, the statements of the holders of these
patents are registered with the IEC. Information may be obtained from:
Address: Meter Patents Development (Pty) Ltd, c/o Spescom Limited – Head Office, P.O. Box 288,
Halfway House 1685, South Africa.
Tel: +27 11 266 1500
Fax: +27 11 266 1532
Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights other than those identified above. IEC shall not be held responsible for identifying any or all such patent
rights.
International Standard IEC 62055-51 has been prepared by working group 15, of IEC
technical committee 13: Electrical energy measurement, tariff and load control.
IEC 62055-51 is complementary to, and is to be read in conjunction with, IEC 62055-41.

– 4 – 62055-51 © IEC:2007(E)
The text of this standard is based on the following documents:
CDV Report on voting
13/1406/CDV 13/1410/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

62055-51 © IEC:2007(E) – 5 –
INTRODUCTION
The IEC 62055 series covers payment systems, encompassing the customer information
systems, point of sales systems, token carriers, payment meters and the respective interfaces
that exist between these entities. At the time of preparation of this part, IEC 62055 comprised
the following parts, under the general title Electricity metering – Payment systems:
Part 21: Framework for standardization
Part 31: Particular requirements – Static payment meters for active energy (classes 1 and 2)
Part 41: Standard transfer specification – Application layer protocol for one-way token
carrier systems
Part 51: Standard transfer specification – Physical layer protocol for one-way numeric and
magnetic card token carriers
Part 52: Standard transfer specification – Physical layer protocol for a two-way virtual token
carrier for direct local connection
The Part 4x series specifies application layer protocols and the Part 5x series specifies
physical layer protocols.
The standard transfer specification (STS) is a secure message protocol that allows
information to be carried between point-of-sale (POS) equipment and payment meters and
caters for several message types such as credit, configuration control, display, and test
instructions. It further specifies devices and codes of practice that allow for the secure
management (generation, storage, retrieval and transportation) of cryptographic keys used
within the system.
The national electricity utility in South Africa (Eskom) first developed and published the STS
in 1993 and transferred ownership to the STS Association in 1998 for management and
further development.
Prior to the development of the STS a variety of proprietary payment meters and POS
equipment had been developed, which were, however, not compatible with each other. This
gave rise to a definite need among the major users to move towards standardized solutions in
addressing operational problems experienced where various types of payment meter and POS
equipment had to be operated simultaneously. An STS was developed that would allow for the
application and inter-operability of payment meters and POS equipment from multiple
manufacturers in a payment metering installation.
The TokenCarrier is the physical device or medium used to transport the information from the
vending system to the payment meter. Two types of token carriers are specified in this part of
IEC 62055, a magnetic card and a numeric token carrier, which have been approved by the
STS Association. New token carriers can be proposed as new work items through the National
Committees or through the STS Association.
Although the main implementation of the STS is in the electricity supply industry, it inherently
provides for the management of other utility services like water and gas. Future revisions of
the STS may allow for other token carrier technologies like smart cards and memory keys with
two-way functionality and to cater for a real-time clock and complex tariffs in the payment
meter.
The STS Association has established a D-type liaison with working gr
...