ISO IEC 7811-7:2018 download.Identification cards — Recording technique — Part 7: Magnetic stripe: High coercivit high density.
1 Scope
ISO IEC 7811-7 is one of a series a standards describing the characteristics for identification cards as defined in the definitions clause and the use of such cards for international interchange.
ISO IEC 7811-7 specifies requirements for a high coercivity magnetic stripe (including any protective overlay) on an Identification card and encoding technique. Ii takes into consideration both human and machine aspects and states minimum requirements.
Coercivity influences many of the quantities specified in ISO IEC 7811-7 but is not Itself specified. The main characteristic of the high coercivity magnetic stripe is its improved resistance to erasure. This is achieved with minimal probability of damage to other magnetic stripes by contact while retaining read compatibility with magnetic stripes as defined in ISO/IEC 7811-2.
ISO IEC 7811-7 provides for a card capacity of approximately 10 times that of a card conforming to ISO/IEC 7811-s The number of tracks has been Increased to 6, each track being approximately half the width of tracks conforming to ISO/IEC 7811-6k located so that readers designed to read these high density tracks will also be able to read cards conforming to ISO/IEC 7811-2 and ISO/IEC 7811.6. Data Is encoded in 8 bit bytes using the MFM encoding technique. Data framing is used to limit error propagation and error correction techniques further improve reliability of reading.
It is the purpose of the 150/ TEC 7811 series of standards to provide criteria to which cards shall perform. No consideration is given within these standards to the amount of use, if any. experienced by the card prior to test. Failure to conform to specified criteria is negotiated between the involved parties.
ISO/IEC 10373.2 specIfies the test procedures used to check cards against the parameters specified In this document.
NOTE Numeric values In the SI and/or Imperial measurement system in ISO IEC 7811-7 may have been rounded oft and are consistent with, but not exactly equal to each other Using either system is correct but intermixing or reconverting values can result In errors. The original design was made using the Imperial measurement system.
2 Normative references
The following documents are referred to in the text In such a way that some or all of their content constitutes requirements of ISO IEC 7811-7. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4287. Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions and surface texture parameters
ISO/IEC 7810, Identification cards — Physical characteristics
ISO/IEC 10373-1, Ident4’i cation cards — Test methods — Part 1: General charaaeristics
ISO/IEC 10373-2, IdentIfication cards — Test methods — Part 2: Cards with magnetic stripes
6.4 Wear of magnetic stripe from read/write head
Average signal amplitude ((IA) and individual signal amplitude (‘J) are measured before and after
2 000 wear cycles and shall result in:
(IA after  0.60 (IA hctwe and Ulaftr 0,80 (IA altrr
6.5 ResIstance to chemicals
Average signal amplitude ((IA) and individual signal amplitude (Uj are measured before and after short term exposure (as defined in the referenced Test Method document) shall result in:
 0,90 UA hetcire and U1 after 090 UA after
Average signal amplitude (U*.) and Individual signal amplitude (hi) are measured before and after long term exposure (24 h) to acid and alkaline artificial perspiration, as defined in the referenced Test Method document.
VA 11j  0,90 VA ure and a 0,90 VA alter
7 Performance characteristics for the magnetic material
7.1 General
The purpose of this cbuse is to enable magnetic interchangeability between card and processing systems. Media coercivity is specified. The media’s performance criteria, regard less of coercivity, is specified in 73..
This method uses a reference card whose material Is traceable to the primary standard (see Clause 3). All signal amplitude results from the use of the secondary reference card must be corrected by the factor supplied with the secondary reference card.
7.2 Testing and operating environment
The testing environment for signal amplitude measurements is 23 °C i 3 °C (73 F ± 5 °F) and 40 % to 60% relative humidity. When tested under otherwise identical conditions, the average signal amplitude measured at 40 ft/mm (1 016 Itpi) shall not deviate from its value in the above test environment by more than 15% after 5 mm exposure over the following operating environment range:
temperature -35°C to 50°C (-31 °F to 122 °F)
relative humidity 5% to 95 %
7.3 Signal amplitude requirements for magnetic media
The requirements for recording characteristics of the card are shown in Tablel FigurcLó, and Figure 7. The media’s performance requirements specified in 73 shall be met in order to achieve improved resistance to erasure, and to enable magnetic interchange between card and processing systems. The properties in Aiuiea.C are Intended as guidelines for magnetic material. AnncxC Is informative and shall not be used as performance criteria for cards.
8 Data structure
The encoding technique for each track shaft be Modified Frequency Modulation (MFM) recording for which the conditions are:
— a flux transition shall be written at the centre of each bit cell containing a ONE:
— a flux transition shall be written at each cell boundary between adjacent bit cells containing ZEROS.
The data shall be recorded as a synchronous sequence of characters without intervening gaps.
NOTE 1 Recording with a write current which is less than I can result In poor quality encoding
NOTE 2 MFM is the same as the FM technique described in ISO/IEC 78116 except that clocking Ilux transitions for 1 bits have been removed. This results in a loss of some of the self-docking feature with FM encoding and requires more accuracy for flux transition intervals. With this technique there may not be a flux transition at the bit cell boundary.
See EigurcB.
9.6 DIrection of recording
The encoding shall begin from the right-hand side viewed from the side with the magnetic stripe and
with the stripe at the top.
9.7 LeadIng and trailing clock bits
The lead-in up to the first FSC shall be recorded with ones and the space after the last FSC shall also be recorded with ones. Ones encoded from the edge of the card to 3,30 mm (0.130 In) In from the edge of the card are not required to meet the specifications given herein.
10 Data structure
User data to be written on the card shall be divided among the tracks used. Each track used shall be of a Fixed length depending on the type of card used requiring the user data to be padded with binary zero bytes if It does not fill the available space on the track(s) used. Data structure on each track is independent of other tracks. The general process for structuring of the data Is shown in TablL.3. see also Figire11.