ECMA 120-1993 DATA INTERCHANGE ON 12 7 mm 18-TRACK MAGNETIC TAPE CARTRIDGES《12 7 mm 18磁道盒式磁带上的数据交换 第3版》.pdf

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1、STD-ECMA ECMA-LZO-ENGL 1993 m 3404593 0032b82 bLL m ECMA EUROPEAN COMPUTER MANUFACTURERS ASSOCIATION STANDARD ECMA-120 DATA INTERCHANGE ON 12,7 mm 18-TRACK MAGNETIC TAPE CARTRIDGES 3rd Edition - December 1993 Free copies of this document are available from ECMA, European Computer Manufacturers Assoc

2、iation, 114 Rue du Rh6ne - CH-120Q Geneva (Switzerland) Phone: 41 22 735 36 34 Fax: 4122 786 52 31 X.400. C=ch, A=arcom, -ma, egenevanet, OUl=ecma, S=helpdesk Internet: helpdeskecma.ch STD-ECMA ECHA-120-ENGL 1993 3404593 003268Y 49Y ECMA EUROPEAN COMPUTER MANUFACTURERS ASSOCIATION STANDARD ECIMA-120

3、 DATA INTERCHANGE ON 12,7mm 18-TRACK MAGNETIC TAPE CARTRIDGES 3rd Edition - December 1993 STD-ECMA ECMA-120-ENGL 1773 3404593 0032685 320 Brief History In 1985 ECMA decided to produce an ECMA Standard for a 12.7 mm, 18-Track Magnetic Tape Cartridge. Considerable work was invested in this project so

4、that an urgently needed standard was developed rapidly and published in December 1986, Upon request of ISO/TC97/SCll this ECMA Standard has been contributed to IS0 for further processing as draft International Standard DIS 9661 under the IS0 fast-track procedure. The requirements for magnetic proper

5、ties were defined in the first edition of Standard ECMA-120 by means of new tests not requiring to relate the performance of the tape under test to that of a Master Standard Reference Tape. Extensive work in severai laboratories, specially in the USA, had shown in the meantime that these new tests p

6、resented more difficulties than originally assessed and that much reliability and simplification could be achieved by reverting to the use of a Master Standard Reference Tape. Such a tape has been established at the National Institute for Standards and Technology (NIST) in Washington, as well as Sec

7、ondary Standard Reference Tapes. As a consequence of these developments IS0 DIS 9661 was reviewed accordingly and the original tests for the magnetic properties were replaced by tests based on the Reference Tape. A small number of numeric values, in particular of the dimensions of the case, were als

8、o amended. A 2nd Edition of Standard ECMA-120 was developed to make it technically identical with International Standard IS0 9661. Standard ECMA-152 is an extension of Standard ECMA-120 and has been accepted under the fast-track procedure as ISO/IEC 11559. The contents of this International Standard

9、 as well as comments raised during the letter ballot of DIS 11559 have led to two Technical Comgenda to IS0 9661 and some remaining comments. A new edition of IS0 9661 includes all these changes, is fully aligned with ISO/IEC 11559, and will be published as ISOW 9661:1994. This 3rd Edition of Standa

10、rd ECMA-120 is technically identical with International Standard ISO/IEC 9661 : 1994. Adopted as the 3rd Edition of ECMA-120 by the General Assembly of December 1993. Table of contents Page Section 1 - General 1 2 3 4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 4.16 4.17 4.18 4

11、.19 4.20 4.21 4.22 5 5.1 5.2 5.3 5.4 scope Conformance References Definitions Avenge Signal Amplitude back surface Beginning of Tape (BOT) byte cartridge Cyclic Redundancy Check chmcter data density Error Correcting Code fiw transition position flux ttansition spacing magnetic tape Master Standard R

12、eference Tape physical recording density Postamble Preamble Reference Field Secondary Standard Reference Tape Standard Reference Amplitude (SRA) Standard Reference Current Test Recording Current hack Typical Field Environment and safety Cartridgenape testing environment Cartridge operation environme

13、nt Cartridge storage environment Safety requirements 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 5.4.1 Safety 5.4.2 Flammability 5.5 Transportation Section 2 - Tape requirements 6 Characteristics of the tape 6.1 Material 6.2 Tape length 6.3 Tape width 6.4 Tape discontinuity 6.5 Toid thickn

14、ess of tape 6.6 Base material thickness 6.7 Longitudinal curvature 6.8 Out-of-phe distortions 6.9 Cupping 6.10 Dynamic frictional characteristics 6.10.1 6.10.2 Frictional id C2 to 5 x lo9 C2 for backcoated tapes. STDmECMA ECMA-120-ENGL I993 W 3404593 0032697 OY2 -7- hoCedure Condition a test piece o

15、f tape to the test environment for 24 hours. Position the test piece over two 24-cara gold-plated, semi-circular electrodes having a radius r = 25.4 mm and a finish of at least N4, so that the recording surface is in contact with each electrode. These electrodes shall be placed parallel to the groun

16、d and parallel to each other at a distance d = 12,7 mm between their centres. Apply a force F of 1,62 N to each end of the test piece. Apply a d.c. voltage of 500 V f 10 V across the electrodes and mwwe the resulting current flow. From this value, determine the electrical resistance. Repeat fur a to

17、tal of five positions along the test piece and average the five resistance readings. For back-coated tape repeat the procedure with the backcoating in contact with the electrodes. t F Figure 2 - Position of test piece over two semi-circular electrodes When mounting the test piece, make sure that no

18、conducting paths exist between the electrodes except that through the coating under test. NOTE 5 Particular atrention should be given 10 keeping the surfaces clean. 6.14 Tape durability This Standard does not specify parameters for assessing tape durability. However, a recommended procedure is descr

19、ibed in annex D. This Standard does not specify parameters for assessing whether or not a tape is an inhibitor tape. However, annex B gives further information on inhibitor tapes. Tape abrasivity is the tendency of the tape to wear the tape transport. The length of the wear pattern on a wear bar sha

20、ll not exceed 56 pm when measured as specified in annex C. 6.15 Inhibitor tape 6.16 Tape abrasivity 6.17 Pre-recording condition Prior to recording data or to testing, the tape shall have been erased using alternating magnetic fields of decaying levels (anhysteretic process) to ensure that the reman

21、ent magnetic moment of the recording surface does not exceed 20 96 of the maximum remanent magnetic moment. Annex E specifies the method of measurement. In addition no low density transitions shall be present on the tape. 6.18 Magnetic recording characteristics The magnetic recording characteristics

22、 shall be as defined by the testing requirements given below. STD-ECMA ECMA-120-ENGL 1993 = 3404593 0032698 Ta9 -8- 6.18.1 6.18.2 6.18.3 6.18.4 When performing these tests, the output or resultant signal shall be measured on the same relative pass for both a tape calibrated to the Master Smdard Refe

23、rence Tape and the tape under test (read-while-write or first forward- read-pass) on the same equipment. The following conditions shall apply to the testing of all magnetic recording characteristics, unless otherwise stated: - tape condition - tapespeed - read-track - azimuth alignment - write-gap l

24、ength - write head saturation density - tape tension - recording current : pre-recording condition : not greater than 2.5 m/s : within the written track : not greater than 6 between the mean write transitions and the read gap : 1,4 pm f 0.2 pm : 0,34 T f 0.03 T : 2.2 N f 0.2 N : Test Recording Curre

25、nt Typical Field The Typical Field of the tape shall be between 90 8 and 110 %I of the Reference Field. Traceability to the Reference Field is provided by the Calibration factors supplied with each Secondary Standard Reference Tape. Signal amplitude The Average Signal Amplitude at the physical recor

26、ding density of 972 ftpmm shall be between 70 8 and 140 I of the SRA. Traceability to the Standard Reference Amplitude is provided by the calibration factors supplied with each Secondary Standard Reference Tape. Resolution The ratio of the Average Signal Amplitude at the physical recording density o

27、f 1 458 ftpmm to that at the physical recording density of 972 ftpmm shall be between 80 8 and 120 % of the same ratio for the Master Standard Reference Tape. Traceability to the resolution of the Master Standard Reference Tape is provided by the calibration factors supplied with each Seconduy Stand

28、ard Reference Tape. Overwrite Overwrite is the ratio of the Average Signal Amplitude of the residual of the fundmenial frequency of a tone pattern after being overwritten at 972 ftpmm to the Average Signal Amplitude of the 972 ftpmm signal. The Average Signal Amplitude of the tone pattern is the ped

29、-to-peak amplitude of the sinusoidal signal with equal rmS power. 6.18.4.1 Requirement The overwrite for the tape shall be less than 120 % of the overwrite for the Master Standard Reference Tape. Traceability to the overwrite of the Master Standard Reference Tape is provided by the calibration facto

30、rs supplied with each Secondary Standard Reference Tape. Procedure Record a tone pattern which shall be the following sequence of flux transitions: STD-ECHA ECMA-120-ENGL 1993 = 3404593 0032699 915 -9- 1 O O O O O 1 O O O O O where: u1 = 1,029 pm a2 = 03 14 pm Record a 972 ftpmm signal over the tone

31、 pattern. Measure the Average Signal Amplitude of the residual of the fundamentai iequency of the tone pattern (one sixth of the equency of the 972 ftpmm signal) and the Average Signal Amplitude of the 972 ftpmm signai. Both amplitude measurements should be made using suitable filters. 6.18.5 Narrow

32、-Band Signal-to-Noise Ratio (NB-SNR) The narrow-band signal-to-noise ratio is the Average Signai Amplitude rms power divided by the average integrated (side band) rms noise power, and is expressed in decibels. 6.185.1 Requirement The NB-SNR ratio shail be equal to, or greater than, 30 dB when normal

33、ized to a track width of 410 p. The normalization factor is dB(410) = a(“) + 10 log 410/W, where W is the rack width used when measuring dB(W). 6.18.5.2 Procedure 6.19 The NB-SNR ratio shall be measured using u spectrum analyzer with a resolution bandwidth (RBW) of 1 Wz and a video bandwidth (VBW) o

34、f 10 Hz. The tape speed shail be 762 mmls for the frequencies specified below. Ihe NB-SNR ratio shall be measured as follows: a) b) Measure the read-signal amplitude of the 972 ftpmm signal, taking a minimum of 150 samples over a minimum length of tape of 46 m. On the next pass (read only) measure t

35、he rms noise power over the same section of tape and integrate the rms noise power (normalizing for the actual resolution bandwidth) over the range from 332 kHz to 366 kHz. For other tape speeds all the frequencies shall be Linearly scaled. Tape quality The tape quality (including the effects of exp

36、osure to storage and transportation environments) is defined by the testing requirements given in the following clauses. The following conditions shall apply to ail quality testing requirements: - environment : operating environment - tape condition : pre-recording condition - tapespeed : 2 m/s - re

37、ad-tnck width : 410 pm - physical recording density : 972 ftprnm - write-gap length : 1,4 prn f 0,2 prn - azimuth alignment - write head saturation density - recording current : Test Recording Current - format : 18 tracks - tape tension : 2,2 N f 0,2 N : not greater than 6 between the mean write tra

38、nsitions and the read gap : 0.34 T f 0,03 T 6.19.1 6.19.2 6.19.3 STDeECMA ECMA-LZO-ENGL II993 3404573 0032700 4b7 = - 10 - Missing puises A missing pulse is a loss of read signal amplitude. A missing pulse exists when the base-to- read signal amplitude is 25 %, or less, of half the Avenge Signal Amp

39、litude for the preceding 25,4 mm of tape. Missing pulse zones A missing pulse zone begins with a missing pulse and ends when 64 consecutive flux transitions are detected or a length of 1 mm of tape has been measured. The missing pulse zone rate shall be less than one in 8 x 106 flux transitions reco

40、rded. Coincident missing pulse zones There are two 9-track groups in the 18-trrick format. One group comprises the odd-numbered tracks, the other group comprises the even-numbered tracks. A simulianeous missing pulse zone condition on two or more tracks of a 9-rack group is a coincident missing puls

41、e zone. If a coincident missing pulse zone occurs at the me time in both groups of tracks, it shrill be considered as a single coincident missing pulse zone. Its length shall begin with the star of the earliest coincident missing puise zone and terminate with the end of the latest coincident missing

42、 pulse zone. No 165 m length of tape shall have more than 12 coincident missing pulse zones. No coincident missing pulse zone shall exceed 50 mm. Section 3 - Cartridge requirements 7 Dimenaonai and mechanical characteristics of the cartridge The cartridge shall consist of the following elements: - a

43、case; - a reel for the magnetic tape; - a magnetic tape wound on the hub of the reei; - a locking mechanism for the reel: - a write-inhibit mechanism; - aleriderblock; - Dimensional characteristics are specified for those parameters deemed mandatory for interchange and compaible use. of lhe cartridg

44、e. Where there is freedom of design, only the functional characteristics of the elements described are indicated. In the figures u typical implemenation is presented. Third angle projection is used. Where they are purely descriptive the dimensions are referred to three reference surfaces A, B and C

45、forming a geometrical trihedral (see figure 3). Where the dimensions m related to the position of the cartridge in the drive, they may be referred to another surface of the cartridge. Figure 4 to 11 show the dimensions of the empty case. Figure 3 a latching mechanism for the leader block. is a gener

46、al view of the whole cartridge; Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 shows the front side of the case which lies in reference surface A shows the top side of the case; shows the rear side of the case; shows the bottom side of the case which lies in refe

47、rence surface C; shows the side of the case which lies in reference surface B; shows an enlarged view of a part (case opening) of figure 4; shows an enlarged cross-section of a location notch: shows an enlarged cross-section of a detail of the opening of the crise; shows an enlarged partial cross-se

48、ction of the cartridge in hand; STD.ECMA ECMA-120-ENGL 1993 3404593 OD32701 3T3 - 11 - Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 shows the same cross-section as figure 12 but of the cartridge in the drive; shows schematically the teeth of the toothed rim: shows two views and an enlarged cros

49、s-section of the leader block; shows the fixation of the tape to the leader block, and shows the leader block inserted in the case. 7.1 Overall dimensions (figures 4 to 6) The overall dimensions of the case shall be I, = 125.00 mm i 0.32 mm J2 = 109, mm f 0.32 mm + 050 mm - 032 mm l3 = 2430 mm The comers of the case shall be rounded off as specified by rl = 3.00 ma. r2 = 4,00 max. r3 = 3.00 min. 7.2 Write-inhibit mechanism (figures 4 and 5) The write-inhibit mechanism shall have a flat surface identified by a visual mark, e.g. a white spot, when in the position in