SIST EN 1088:2000+A2:2008
(Main)Safety of machinery - Interlocking devices associated with guards - Principles for design and selection
Safety of machinery - Interlocking devices associated with guards - Principles for design and selection
This standard specifies principles for the design and selection - independent of the nature of the energy source - of interlocking devices associated with guards (as defined in 3.23.1 "interlocking de vice (interlock)", 3.22.4 "interlocking guard" and 3.22.5 "interlocking guard witg guard locking" of EN 292-1:1991). It also provides requirements specifically intended for electrical in terlocking devices. This standard covers the parts of guards which actuate interlocking devices. Requirements for guards are given in prEN 953. The processing of the signal from the interlocking device to stop and immobilize the machine is dealt with in prEN 954-1.
Sicherheit von Maschinen - Verriegelungseinrichtungen in Verbindung mit trennenden Schutzeinrichtungen - Leitsätze für Gestaltung und Auswahl
Diese Norm legt Prinzipien für Gestaltung und Auswahl von Verriegelungseinrichtungen in Verbindung mit trennenden Schutzeinrichtungen fest — unabhängig von der Energieart — (wie in EN 292-1:1991, 3.23.1 "Verriegelungseinrichtung [Verriegelung]"; EN 292-1:1991, 3.22.4 "verriegelte trennende Schutzeinrichtung" und EN 292-1:1991, 3.22.5 "verriegelte trennende Schutzeinrichtung mit Zuhaltung" festgelegt).
Weiterhin enthält sie Anforderungen speziell für elektrische Verriegelungseinrichtungen (siehe Abschnitt 6).
Diese Norm umfasst die Teile einer trennenden Schutzeinrichtung, die Verriegelungseinrichtungen betätigen. Anforderungen für trennende Schutzeinrichtungen sind in prEN 953 aufgeführt. Die Verarbeitung des von der Verriegelungseinrichtung ausgehenden Signals zum Anhalten und Stillsetzen der Maschine wird in prEN 954-1 behandelt.
Sécurité des machines - Dispositifs de verrouillage associés à des protecteurs - Principes de conception et de choix
La présente norme spécifie des principes de conception et de choix — indépendamment de la nature de la source d’énergie — des dispositifs de verrouillage associés à des protecteurs (tels que définis en 3.23.1 «dispositif de verrouillage», 3.22.4 «protecteur avec dispositif de verrouillage» et 3.22.5 «protecteur avec dispositif d’interverrouillage» de l’EN 292-1:1991).
Elle fournit également des prescriptions technologiques spécifiquement destinées aux dispositifs de verrouillage électrique (voir l’Article 6).
Cette norme couvre les parties des protecteurs qui actionnent les dispositifs de verrouillage. Les prescriptions relatives aux protecteurs sont données dans le prEN 953. Le traitement du signal issu du dispositif de verrouillage et entraînant l’arrêt et l’immobilisation de la machine est pris en considération dans le prEN 954 1.
Varnost strojev - Zaporne naprave, povezane z varovali - Načela za načrtovanje in izbiro
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.L]ELURSicherheit von Maschinen - Verriegelungseinrichtungen in Verbindung mit trennenden Schutzeinrichtungen - Leitsätze für Gestaltung und AuswahlSécurité des machines - Dispositifs de verrouillage associés à des protecteurs - Principes de conception et de choixSafety of machinery - Interlocking devices associated with guards - Principles for design and selection13.110Varnost strojevSafety of machineryICS:Ta slovenski standard je istoveten z:EN 1088:1995+A2:2008SIST EN 1088:2000+A2:2008en,fr,de01-december-2008SIST EN 1088:2000+A2:2008SLOVENSKI
STANDARD
SIST EN 1088:2000+A2:2008
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 1088:1995+A2
July 2008 ICS 13.110 Supersedes EN 1088:1995 English Version
Safety of machinery - Interlocking devices associated with guards - Principles for design and selection
Sécurité des machines - Dispositifs de verrouillage associés à des protecteurs - Principes de conception et de choix
Sicherheit von Maschinen - Verriegelungseinrichtungen in Verbindung mit trennenden Schutzeinrichtungen -Leitsätze für Gestaltung und Auswahl This European Standard was approved by CEN on 13 November 1995 and includes Amendment 1 approved by CEN on 8 March 2007and Amendement 2 approved by CEN on 6 June 2008.
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 CEN 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 CEN Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, 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 © 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1088:1995+A2:2008: ESIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 2 Contents Page Foreword.4 Introduction.5 1 Scope.5 2 Normative references.5 3 Definitions.6 4 Operating principles and typical forms of interlocking devices associated with guards.8 4.1 Interlocking principles.9 4.2 Typical forms of interlocking devices.9 4.3 Technological forms of interlocking devices.13 5 Provisions for the design of interlocking devices (independent of the nature of the energy source).13 5.1 Actuation modes of mechanically actuated position detectors.13 5.2 Arrangement and fastening of position detectors.14 5.3 Arrangement and fastening of cams.15 5.4 Reducing the possibility of common cause failures.15 5.5 Guard locking device (see 3.4 and 4.2.2).16 5.6 Delay devices.16 5.7 !!!! Design to minimize defeat possibilities"""".16 5.8 Environmental considerations.20 6 Additional technological requirements for electrical interlocking devices.20 6.1 Compliance with EN 60204-1.20 6.2 Interlocking devices incorporating mechanically actuated position switches.20 6.3 Interlocking devices incorporating non-mechanically actuated position switches (proximity switches and magnetic switches).21 7 Selection of an interlocking device.21 7.1 General.21 7.2 Conditions of use and intended use.22 7.3 Risk assessment.22 7.4 Stopping time and access time.22 7.5 Frequency of access (frequency of opening the guard for access to the danger zone).22 7.6 Performance considerations.23 Annex A (informative)
Guard-operated interlocking device with one single cam-operated position detector (see Introduction).24 Annex B (informative)
Guard-operated interlocking device with tongue-operated switch (see Introduction).26 Annex C (informative)
Direct (mechanical) interlocking between guard and start/stop manual control (see Introduction).27 Annex D (informative)
Captive-key interlocking device (see Introduction).28 Annex E (informative)
Trapped-key interlocking device (see introduction).30 Annex F (informative)
Plug and socket interlocking device [plug/socket combination] (see Introduction).32 Annex G (informative)
Guard-operated interlocking device incorporating two cam-operated position detectors (see Introduction).34 SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 3 Annex H (informative)
Mechanical interlocking between a guard and a movable element (see Introduction).36 Annex J (informative)
Electrical interlocking device incorporating magnetically actuated [magnetic] switches (see Introduction).37 Annex K (informative)
Electrical interlocking device incorporating two proximity detectors (see Introduction).38 Annex L (informative)
Pneumatic/hydraulic interlocking devices (see Introduction).39 Annex M (informative)
Interlocking device with spring applied/power released guard locking device (see Introduction).41 Annex N (informative)
Interlocking device with guard locking, with manually operated delay device (see Introduction).43 Annex ZA (informative)
#Relationship between this European Standard and the Essential Requirements of EU Directive 98/37/EC$.44 Annex ZB (informative)
#Relationship between this European Standard and the Essential Requirements of EU Directive 2006/42/EC$.45 Bibliography.46
SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 4 Foreword This document (EN 1088:1995+A2:2008) has been prepared by Technical Committee CEN/TC 114 “Safety of machinery”, the secretariat of which is held by DIN. The drafting was carried out by a working group (WG 10) of CEN/TC 114. 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 January 2009, and conflicting national standards shall be withdrawn at the latest by January 2009. This document includes Amendment 1, approved by CEN on 2007-03-08 and Amendment 2, approved by CEN on 2008-06-06. This document supersedes EN 1088:1995. The start and finish of text introduced or altered by amendment is indicated in the text by tags ! " and #$. !This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s). For relationship with EU Directive(s), see informative Annexes ZA and ZB, which are integral parts of this document." This standard is a type B2 standard in accordance with EN 414. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 5 Introduction This standard has been prepared to be a harmonised standard to provide one means of conforming with the essential safety requirements of the Machinery Directive and associated EFTA Regulations. Its primary purpose is to give guidance to machinery designers and writers of type C standards on how to design or to select interlocking devices associated with guards with a view to complying with the relevant essential safety requirements of the EC Machinery Directive (see Foreword). It may also be used as guidance in controlling the risk where there is no type C standard for a particular machine. Relevant sections of this standard, used alone or in conjunction with provisions from other standards, can be used as a basis for verification procedures for the suitability of a device for interlocking duties. A statement by a manufacturer that an interlocking device complies with EN 1088, without reference to specific clauses, has no meaning. The annexes A, B…, P are informative. Annexes A to N contain only examples complying with the principles set out in this standard, and the application of which has been validated by experience. Other solutions may be adopted, provided that they comply with the same principles. Annex P is entitled "Bibliography". 1 Scope This standard specifies principles for the design and selection - independent of the nature of the energy source – of interlocking devices associated with guards (as defined in 3.23.1 "interlocking device [interlock]", 3.22.4 "interlocking guard" and 3.22.5 "interlocking guard with guard locking" of EN 292-1:1991). It also provides requirements specifically intended for electrical interlocking devices (see clause 6). This standard covers the parts of guards which actuate interlocking devices. Requirements for guards are given in prEN 953. The processing of the signal from the interlocking device to stop and immobilize the machine is dealt with in prEN 954-1. 2 Normative references This European Standard incorporates, by dated or undated reference, 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. EN 292-1:1991, Safety of machinery – Basic concepts, general principles for design – Part 1: Basic terminology, methodology EN 292-2:1991, Safety of machinery – Basic concepts, general principles for design – Part 2: Technical principles and specifications EN 294:1992, Safety of machinery – Safety distances to prevent danger zones being reached by the upper limbs prEN 953, Safety of machinery – General requirements for the design and construction of guards (fixed, movable) SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 6 prEN 954-1, Safety of machinery – Safety-related parts of control systems – Part 1: General principles for design prEN 999, Safety of machinery – The positioning of protective equipment in respect of approach speed of parts of the human body prEN 1037, Safety of machinery – Prevention of unexpected start-up prEN 1050, Safety of machinery – Principles for risk assessment EN 60204-1:1992, Safety of machinery – Electrical equipment of machines – Part 1: General requirements EN 60947-5-1:1991, Low-voltage switchgear and controlgear - Part 5: Control circuit devices and switching elements – Section 1: Electromechanical control circuit devices (IEC 947-5-1:1990) 3 Definitions For the purposes of this standard the following definitions apply: 3.1 interlocking device [interlock] mechanical, electrical or other type of device, the purpose of which is to prevent the operation of machine elements under specified conditions (generally as long as a guard is not closed). [3.23.1 of EN 292-1:1991] 3.2 Interlocking guard guard associated with an interlocking device, so that: the hazardous machine functions "covered" by the guard cannot operate until the guard is closed; if the guard is opened while the hazardous machine functions are operating, a stop instruction is given; when the guard is closed, the hazardous machine functions "covered" by the guard can operate, but the closure of the guard does not by itself initiate their operation. [3.22.4 of EN 292-1:1991] NOTE In English "stop signal" and "stop command" are synonyms for "stop instruction". In German "Stop-Signal" and "Stop-Befehl" are synonyms for "Halt-Befehl". In French "ordre d'arrêt" is an all-encompassing term 3.3 interlocking guard with guard locking guard associated with an interlocking device and a guard locking device so that: the hazardous machine functions "covered" by the guard cannot operate until the guard is closed and locked; the guard remains closed and locked until the risk of injury from the hazardous machine functions has passed; when the guard is closed and locked, the hazardous machine functions "covered"
by the guard can operate, but the closure and locking of the guard do not by themselves initiate their operation. [3.22.5 of EN 292-1:1991] SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 7 3.4 guard locking device device intended to lock a guard in the closed position and linked to the control system so that: the machine cannot operate until the guard is closed and locked; the guard remains locked until the risk has passed. 3.5 automatic monitoring a back-up safety function which ensures that a safety measure is initiated if the ability of a component or an element to perform its function is diminished, or if the process conditions are changed in such a way that hazards are generated. There are two categories of automatic monitoring: "continuous" automatic monitoring, whereby a safety measure is immediately initiated when a failure occurs; "discontinuous" automatic monitoring, whereby a safety measure is initiated during a following machine cycle, if a failure has occurred. [3.14 of EN 292-1:1991] 3.6 positive mode actuation if a moving mechanical component inevitably moves another component along with it, either by direct contact or via rigid elements, the second component is said to be actuated in the positive mode (or positively) by the first one. [based on 3.5 of EN 292-2:1991] 3.7 positive opening operation of a contact element the achievement of contact separation as the direct result of a specified movement of the switch actuator through non-resilient members (e.g. not dependent upon springs). [2.2 of chapter 3 "Special requirements for control switches with positive opening operation" of EN 60947-5-1:1991]. NOTE For fluid power, the equivalent concept may be called "positive mode interruption". 3.8 stopping time (time for hazard elimination) the period between the point at which the interlocking device initiates the stop command and the point at which the risk from hazardous machine functions has passed. 3.9 access time [time for access to a danger zone] the time taken to access the hazardous machine parts after initiation of the stop command by the interlocking device, as calculated on the basis of an approach speed the value of which may be chosen, for each particular case, taking into account the parameters given in prEN 999 "Safety of machinery – The positioning of protective equipment in respect of approach speeds of parts of the human body". SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 8 4 Operating principles and typical forms of interlocking devices associated with guards NOTE Reference is made to the relevant informative annexes where it is considered useful for clearer understanding.
*) in accordance with prEN 1037 Figure 1 — Location of interlocking devices in machinery [based on Annex A of EN 292-1] SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 9
4.1 Interlocking principles 4.1.1 Control interlocking The stop command from the interlocking device is introduced into the control system so that interruption of the energy supply to the machine actuators – or mechanical disconnection of moving parts from the machine actuators – is triggered by the control system (indirect interruption: levels A and B in figure 1). 4.1.2 Power interlocking The stop command from the interlocking device directly interrupts the energy supply to the machine actuators or disconnects moving parts from the machine actuators (level C in figure 1). "Directly" means that, unlike control interlocking (see 4.1.1), the control system does not play any intermediate role in the interlocking function. 4.2 Typical forms of interlocking devices 4.2.1 Interlocking device (without guard locking) (see table 1 and figure 3a)) It is always possible to open the guard. As soon as the guard is no longer closed, the interlocking device generates a stop command. As it is possible to start opening the guard during operation of the machine (or of the hazardous machine elements), the function is that of an interlocking device, as defined in 3.22.4 of EN 292-1:1991. Examples of interlocking devices without guard locking are shown in annexes A, B, F, G, J, K, L. 4.2.2 Interlocking device with guard locking (see table 1 and figure 3b)) The guard is held closed by a guard locking device (see 3.4). There are two types of devices: those where unlocking the guard can be initiated at any time by the operator (unconditional unlocking: see table 1 and figure 3b1)); those where unlocking the guard is possible only if a condition is fulfilled, thus ensuring that the hazard has disappeared (conditional unlocking: see table 1 and figure 3b2)). The guard locking device (see 3.4) can be an integral part of an interlocking device, or a separate unit. In a guard locking device, the part which is intended to lock/unlock the guard can be: manually applied, manually released (see figure N.1 in annex N); spring applied, power released (see figure 2a)); power applied, spring released (see figure 2b)); power applied, power released (see figure 2c)). SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 10
a) spring applied… …power released
b) power applied… …spring released
c) power applied… …power released
Figure 2 — Operating modes of the guard locking device in power-actuated guard locking devices Examples of interlocking devices with guard locking are given in annexes C, D, E, H, M, N. SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 11
a) interlocking device without guard locking ("two-state interlocking")
b1) Unconditional unlocking ("three-state interlocking") b2) Conditional unlocking ("four-state interlocking")
b) interlocking devices with guard locking Figure 3 — Functional diagrams of the different types of interlocking devices SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 12 Table 1 — Various aspects of the interlocking devices with and without guard locking Interlocking devices without guard locking (see 4.2.1 and figure 3a))
Interlocking devices with guard locking (see 4.2.2 and figure 3b))
Conditional unlocking (see figure 3b2)) Unlocking the guard is made possible only if (or is triggered when) one of the following conditions is fulfilled:
Unconditional unlocking (see figure 3b1)) Unlocking the guard can be started at any time by the operator, but the time necessary for the guard to be unlocked is longer than the time necessary for the hazard to disappear - a fixed time**) has elapsed after the stop command has been given; - disappearance of the hazzard has been detected (e.g. zero-speed detection).
Stop command given: - at the beginning of the guard opening stroke (the interlocking device is actuated by the guard itself); - simultaneously with the beginning of the actuation of the lock*) and as a consequence of it; - shortly after the beginning of the actuation of the guard locking device and as a consequence of it; - by the operator, or automatically by the control system, then memorized by the interlocking device.
(see annexes A, G)
(see annex D)
(see annex N)
(see annex M) Typical examples *) Strictly speaking, the guard is unlocked after the beginning of the stop command. Where the hazard disappears "as soon as the stop command is given" (in any case before the guard is unlocked), the function ensured is equivalent to that of an interlocking guard with guard locking. **) Longer than the time necessary for the hazard to disappear.
SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 13 4.3 Technological forms of interlocking devices Interlocking techniques involve a broad spectrum of technological aspects. As such, interlocking devices can be classified using a great variety of criteria, e.g. the nature of the link between guard and circuit-opening elements, or the technological type (electromechanical, pneumatic, electronic, etc.) of the circuit-opening elements. Table 2 establishes the link between the main technological forms of interlocking devices and the parts of this standard which deal with them. Table 2 — Technological forms of interlocking devices
Technological forms Provisions in clauses Examples in annexes Interlocking devices with mechanically actuated detectors: - with cam-operated detectors; - with tongue-operated detectors. 5.1 to 5.4, 5.7.2, 6.2
5.7.2.1 5.7.2.2
A, G, L, M B Interlocking devices with non-mechanically actuated detectors: - with magnetically actuated switches; - with electronic proximity switches.
5.7.3 – 6.3 5.7.3 – 6.3
J K Systems incorporating keys: - captive-key systems; - trapped-key systems.
D E Plug and socket systems 5.7.4 F Mechanical interlocking between guard and movable parts
H
5 Provisions for the design of interlocking devices (independent of the nature of the energy source) 5.1 Actuation modes of mechanically actuated position detectors
When a single detector is used to generate a stop command, it shall be actuated in the positive mode (see table 3 and 3.6). Non-positive mode actuation is only allowed in conjunction with a detector with positive mode actuation, notably to avoid common cause failures (see 5.4.1). The design of the actuator should be as simple as possible, since this may reduce the probability of failure. SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 14
Table 3 — Actuation of position detectors in the positive mode and in the non-positive mode Mode of actuation Guard closed Guard open Working mode POSITIVE MODE
The detector stem (actuator) is held depressed by a cam as long as the guard is open. When the guard is closed, the detector changes its state as the result of the action of a return spring. NON-POSITIVE MODE
The detector stem (actuator) is held depressed by a cam as long as the guard is closed. When the guard is opened, the detector changes its state as the result of the action of a return spring.
5.2 Arrangement and fastening of position detectors 5.2.1 Position detectors shall be arranged so that they are sufficiently protected against a change of their position. In order to meet this requirement: the fasteners of the position detectors shall be reliable and loosening them shall require a tool; the use of slots shall be limited to initial adjustment; provisions shall be made for positive location after adjustment (e.g. by means of pins or dowels). Replacement of the detectors shall be possible without any readjusting need. 5.2.2 In addition, the following requirements shall be met: self-loosening or easy defeat of the detector and of its actuator shall be prevented; the support for position detectors shall be sufficiently rigid to maintain correct operation of the position detector; the movement produced by mechanical actuation shall remain within the specified operating range of the position detector to ensure correct operation and/or prevent overtravel; SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 15 displacement of the guard before the position detector changes its state shall not be sufficient as to impair the protective effect of the guard (for access to danger zones, see EN 294 and prEN 953); the position detectors shall not be used as mechanical stops; the position detectors shall be located and, if necessary, protected so that damage from foreseeable external causes is avoided; easy access to position detectors for maintenance and checking for correct operation shall be ensured. 5.3 Arrangement and fastening of cams Rotary and linear cams for mechanically actuating position detectors shall be designed so that: they are positively located, and fixed by fasteners requiring a tool for loosening them; their self-loosening is prevented; they can only be mounted in a correct position; they do not damage the position detector or impair its durability. NOTE These provisions exclude friction assemblies 5.4 Reducing the possibility of common cause failures When switching elements have been made redundant, common cause failures shall be avoided, e.g. by use of the measures described in 5.4.1 and/or in 5.4.2. 5.4.1 Positive and non-positive mode association of mechanically actuated position detectors (see 5.1)
Key 1 guard closed 2 guard open 3 positive actuation mode 4 non-positive actuation mode Figure 4 — Avoiding common cause failure of two mechanically actuated position detectors by using associated positive and non-positive mode actuation SIST EN 1088:2000+A2:2008
EN 1088:1995+A2:2008 (E) 16 Typical causes for failure of mechanically actuated position detectors are: a) excessive wear of the actuator (e.g. plunger or roller) or of the cam attached to the guard; misalignment between cam and actuator; b) jamming of the actuator (plunger) making actuation by the spring impossible. Detectors actuated in the positive mode, as D1 (see figure 4), fail to danger in case a), but not in case b). Detectors actuated in the non-positive mode, as D2 (see figure 4), fail to danger in case b) but not in case a). S
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.