1、 TECHNICAL REPORT ISA-TR18.2.3-2015 Basic Alarm Design Approved 12 June 2015 ISA-TR18.2.3-2015, Basic Alarm Design ISBN: 978-1-941546-63-5 Copyright 2015 by the International Society of Automation. All rights reserved. Printed in the United States of America. No part of this publication may be repro
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3、isa.org 3 ISA-TR18.2.3-2015 Preface This preface, as well as all footnotes, is included for information purposes only and is not part of ISA-TR18.2.3-2015. This technical report has been prepared as part of the service of ISA, the International Society of Automation, toward a goal of uniformity in t
4、he field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments and criticisms and asks that they be addressed to the Secretary, Standards and Practices Board; ISA, 67 Alexander Drive; P
5、.O. Box 12277; Research Triangle Park, NC 277099; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org.This ISA Standards and Practices Department is aware of the growing need for attention to the metric system of units in general, and the International System of Units (SI) in part
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17、 THIS VERSION. The following served as active members of ISA18 Work Group 3 (WG3) to develop this technical report: NAME COMPANY Todd Stauffer, Co-Chair Exida Co. Patrick ODonnell, Co-Chair BP Joseph Alford Consultant Alan Bryant Oxy Inc. Bill Hollifield PAS Colin Lunty Suncor Douglas Metzger DPM Co
18、nsulting Arshad Muhammad Emerson Process Management Graham Nasby Eramosa Engineering Inc. Harry Pigler Pigler Automation LLC Nicholas Sands DuPont David Strobhar Beville Engineering Inc. Kim Van Camp Emerson Process Management The following people acted as voting members of ISA18 in approving public
19、ation of this technical report: NAME COMPANY Donald Dunn, Co-Chair Phillips 66 Nicholas Sands, Co-Chair DuPont Joseph Alford Consultant Stephen Apple Schneider-Electric John Bogdan J. Bogdan Consulting LLC Kevin Brown Enbridge Inc. Alan Bryant Oxy Inc. Michael Carter SIS-TECH Solutions Lieven Dubois
20、 UReason Bridget Fitzpatrick Wood Group Mustang Inc. Bill Hollifield PAS Sakthivel Kandasamy Chevron Energy Technology Co. Darwin Logerot ProSys Inc. Colin Lunty Suncor Michael Marvan Matrikon Inc. Douglas Metzger DPM Consulting Leila Myers Consultant Graham Nasby Eramosa Engineering Inc. Patrick OD
21、onnell BP George Plowman Rockwell Automation Douglas Rothenberg D Roth Inc. Todd Stauffer Exida Co. David Strobhar Beville Engineering Inc. Beth Vail URS PS / AECOM Kim Van Camp Emerson Process Management 5 ISA-TR18.2.3-2015 David Visnich Burns systematically compare alarms to the alarm philosophy;
22、and determine the alarm setpoint, consequence, operator action, priority, and class. Activities include, but are not limited to, identification, justification, prioritization, classification, and documentation. ISA-TR18.2.3, Basic Alarm Design TR3, provides guidance on basic alarm design. TR3 focuse
23、s on the scope of Clause 10 of ISA-18.2 and may include other clauses as needed (e.g., Clause 14 on operations and Clause 15 on maintenance). Basic alarm design covers the selection of alarm attributes (e.g., types, deadbands, and delay times) and may be specific to each control system. ISA-TR18.2.4
24、, Enhanced and Advanced Alarm Methods TR4, provides guidance on enhanced and advanced alarm methods. TR4 focuses on the scope of Clause 12 of ISA-18.2. Enhanced alarm design covers guidance on additional logic, programming, or modeling used to modify alarm behavior. These methods may include: dynami
25、c alarming, state-based alarming, adaptive alarms, logic-based alarming, and predictive alarming, as well as most of the designed suppression methods. ISA-TR18.2.5, Alarm Monitoring, Assessment, and Audit TR5, provides guidance on monitoring, assessment and audit of alarms. TR5 focuses on the scope
26、of Clauses 16 and 18 in ISA-18.2. Monitoring, assessment, and audit cover the continuous monitoring, periodic performance assessment, and recurring audit of the alarm system. ISA-TR18.2.6, Alarm Systems for Batch and Discrete Processes TR6, provides guidance on the application of ANSI/ISA-18.02-2009
27、 alarm lifecycle activities to batch and discrete processes, expanding on multiple clauses of ISA-18.2. ISA-TR18.2.7, Alarm Management when Utilizing Packaged Systems TR7, provides guidance on the application of ANSI/ISA-18.2-2009 to plants utilizing packaged systems, expanding on multiple clauses o
28、f ANSI/ISA-18.02-2009. The guidance as presented in this document is general in nature, and should be applied to each system as appropriate by personnel knowledgeable in the manufacturing process and control systems to which it is being applied. This guidance will evolve with experience and technolo
29、gy advancements. ISA-TR18.2.3-2015 12 Introduction Alarm Management Lifecycle ISA-18.2 defines requirements that address alarm systems for facilities in the process industries to improve safety, quality, and productivity. The general principles and processes in ISA-18.2 are intended for use in the l
30、ifecycle management of an alarm system based on programmable electronic controller- and computer-based Human-Machine Interface (HMI) technology. These requirements are presented in the standard, using the alarm management lifecycle shown in Figure 1. Note 1: The box used for stage B represents a pro
31、cess defined outside of ISA-18.2. Note 2: The independent stage J represents a process that connects to all other lifecycle stages. Note 3: The rounded shapes of stages A, H, and J represent entry points to the lifecycle. Note 4: The dotted lines represent the loops in the lifecycle. Figure 1 Alarm
32、management lifecycle (ISA-18.2, Figure 2) Monitoring b) numeric calculations within the control system used with basic alarming, such as rate calculations (producing rate-of-change alarms), statistical calculations (producing statistical alarms, such as alarming on standard deviations, etc.) and oth
33、er complex calculations; c) simple to complex models used to estimate process values online, often referred to as virtual sensors; d) high-speed counters and accumulators, often needed in discrete manufacturing applications, which accumulate and aggregate within the control system before applying ba
34、sic alarming; e) logic calculations within the control system to create an alarm only when it is a valid alarm (e.g., a calculation including a logical AND of low pressure and the associated pump run status to create a logical PV that is alarmed). NOTE If the alarm is created by the control system,
35、and logic is added to conditionally suppress it, this falls under the definition of advanced alarming and is discussed in TR4. 1.2.2 Enhanced and advanced alarm methods The enhanced and advanced alarm methods in TR4 include ways to modify alarm attributes dynamically for one or more process variable
36、s. Different from basic alarm design, advanced alarm design often has a larger scope (applies to multiple variables at once) and ensures that alarm attributes track the process (are relevant for different operating states). Additional layers of logic, programming, modelling, or a combination thereof
37、 beyond basic alarming methods, are used to ISA-TR18.2.3-2015 16 modify alarm behavior to ensure alarms are relevant when presented to the operator or to improve operator guidance to better meet the performance objectives of an alarm system. The techniques outlined in TR4 include the following examp
38、les: a) advanced alarm methods provide ways to modify alarm behaviors, through such techniques as designed suppression and state-based alarming; b) enhanced alarm methods provide ways to augment alarms with better operator guidance, including identification of causes, and redirecting the alarm to th
39、e location of the desired responder. 2 Normative references ISA-18.2, ANSI/ISA-18.02-2009, Management of Alarm Systems for the Process Industries, also known as ISA-18.2. ISA-84, ANSI/ISA-84.00.01-2004 (parts 1-3), Safety Instrumented Systems for the Process Industry Sector. 3 Definition of terms an
40、d acronyms Defined terms are used in this technical report. Synonymous terms, which are not used in this technical report, are listed in parentheses. 3.1 Definitions For the purposes of this technical report, the following definitions apply. A complete list of alarm definitions can be found in ISA-1
41、8.2 Clause 3.1. 3.1.1 Absolute alarm Source: ISA-18.2 An alarm generated when the setpoint is exceeded. 3.1.2 Activate Source: ISA-18.2 The process of enabling an alarm function within the alarm system. 3.1.3 Adaptive alarm An alarm whose setpoint is adapted automatically based on process conditions
42、. 3.1.4 Adjustable alarm (Operator-set alarm) Source: ISA-18.2 An alarm for which the setpoint can be changed manually by the operator. 3.1.5 Advanced alarming Source: ISA-18.2 A collection of techniques (e.g., state-based alarming, and dynamic prioritization) that can help manage alarm rates in spe
43、cific situations. 3.1.6 Alarm Source: ISA-18.2 An audible and/or visible means of indicating to the operator an equipment malfunction, process deviation, or abnormal condition requiring a response. 3.1.7 Alarm attributes (Alarm parameters) Source: ISA-18.2 The settings for an alarm within the proces
44、s control system (e.g., alarm setpoint, alarm priority). 3.1.8 Alarm deadband (Alarm hysteresis) Source: ISA-18.2 The change in signal from the alarm setpoint necessary to clear the alarm. 17 ISA-TR18.2.3-2015 3.1.9 Alarm message Source: ISA-18.2 A text string displayed with the alarm indication tha
45、t provides additional information to the operator (e.g., operator action). 3.1.10 Alarm off-delay (Debounce) Source: ISA-18.2 The time a process measurement remains in the normal state before the alarm is cleared. 3.1.11 Alarm on-delay Source: ISA-18.2 The time a process measurement remains in the a
46、larm state before the alarm is annunciated. 3.1.12 Alarm philosophy Source: ISA-18.2 A document that establishes the basic definitions, principles, and processes to design, implement, and maintain an alarm system. 3.1.13 Alarm priority Source: ISA-18.2 The relative importance assigned to an alarm wi
47、thin the alarm system to indicate the urgency of response (e.g., seriousness of consequences and allowable response time). 3.1.14 Alarm setpoint (Alarm limit, Alarm trip point) Source: ISA-18.2 The threshold value of a process variable or discrete state that triggers the alarm ind ication. 3.1.15 Al
48、arm summary Source: ISA-18.2 A display that lists alarms with selected information (e.g., date, time, priority, and alarm type). 3.1.16 Alarm type (Alarm condition) Source: ISA-18.2 A specific alarm on a process measurement (e.g., low process variable alarm, high process variable alarm, or discrepan
49、cy alarm). 3.1.17 Allowable response time Source: ISA-18.2 The maximum time between the annunciation of the alarm and the time the operator must take corrective action to avoid the consequence. 3.1.18 Annunciated alarm An alarm that has been communicated to the operator. 3.1.19 Bad measurement alarm Source: ISA-18.2 An alarm generated when the signal for a process measurement is outside the expected range (e.g., 3.8mA for a 4-20mA signal). 3.1.20 Bit-pattern alarm Source: ISA-18.2 An alarm that is gene
