ISO/IEC 7811-7:2018 pdf download -Identification cards — Recording technique — Part 7: Magnetic stripe: High coercivity, high density.
4 Conformance A prerequisite for conformance with this document is conformance with ISO/IEC 7810. An identification card is in conformance with this document if it meets all mandatory requirements specified herein. Default values apply if no others are specified. 5 Physical characteristics of the identification card 5.1 General The identification card shall conform to the specification given in ISO/IEC 7810. WARNING — The attention of card issuers is drawn to the fact that information held on the magnetic stripe may be rendered ineffective through contamination by contact with dirt and certain commonly used chemicals including plasticizers. It should also be noted that any printing or screening placed on top of the magnetic stripe must not impair the function of the magnetic stripe. 5.2 Magnetic stripe area warpage Application of a 2,2 N (0.5 lbf) load evenly distributed on the front face opposite the magnetic stripe shall bring the entire stripe within 0,08 mm (0.003 in) of the rigid plate. 5.3 Surface distortions There shall be no surface distortions, irregularities or raised areas on both the front and the back of the card in the area shown in Figure 1 that might interfere with the contact between the magnetic head and magnetic stripe.
7 Performance characteristics for the magnetic material 7.1 General The purpose of this clause is to enable magnetic interchangeability between card and processing systems. Media coercivity is not specified. The media’s performance criteria, regardless of coercivity, is specified in 7.3. 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 ± 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 ftpi) shall not deviate from its value in the above test environment by more than 15 % after 5 min 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 Table 1, Figure 6, and Figure 7. The media’s performance requirements specified in 7.3 shall be met in order to achieve improved resistance to erasure, and to enable magnetic interchange between card and processing systems. The properties in Annex C are intended as guidelines for magnetic material. Annex C is informative and shall not be used as performance criteria for cards.
8 Data structure The encoding technique for each track shall 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 min can result in poor quality encoding. NOTE 2 MFM is the same as the FM technique described in ISO/IEC 7811-6 except that clocking flux transitions for 1 bits have been removed. This results in a loss of some of the self-clocking 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.
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 Table 3, see also Figure 11.