DOCSLIB.ORG

CP1382 'Clarification of IDD Rules for Leading Zeroes'

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
CP1382 'Clarification of IDD Rules for Leading Zeroes' 140/03 CP Progression – CP1382 Meeting Name Imbalance Settlement Group Meeting Date 18 December 2012 Purpose of paper For Decision This report provides details of the background, solution, impacts and industry views for Summary CP1382 ‘Clarification of IDD Rules for Leading Zeroes’. ELEXON invites the ISG to approve the CP for implementation in the June 2013 Release. 1. Why change? Background 1.1 The NETA Interface Definition and Design (IDD) Part 1 contains a definition of the decimal data type (n,d) that is misleading in its treatment of leading zeroes. A leading zero is a ‘0’ digit that leads a number string and which does not increase the numerical value of the data. For example, the zeroes in the string 0002568 are all leading zeroes. In usual decimal notation, leading zeroes are not used other than the zero before the decimal point. 1.2 The full set of rules is contained in Section 2.2.3 (page 15) of the IDD as follows: n must be greater than or equal to d optional leading “-“ for negative numbers no leading zeros, except where n = d, then number starts “0.” no trailing zeros maximum n digits maximum d digits after decimal point maximum (n-d) digits before decimal point, except where n=d, then number starts with “0.” field may have “-“; from 1 to (n-d) digits; and optionally “.” and up to d digits. Thus the maximum field width is n+2 in the case of a negative value, except for the special case of n=d, where the maximum field width is n+3 including the leading zero. e.g.: -123.456 is decimal (6,3) -0.123 is a decimal (3,3) To clarify the valid values between 1 and -1, the value 0.123 can be represented as: 0.123 or .123 ISG140/03 – CP1382 Progression Paper Version 1.0 Page 1 of 5 © ELEXON 2012 140/03 but not: 00.123 or 0.1230 Valid representations of zero are: 0 0.0 .0 0. -0 -0.0 -.0 -0. but not as a decimal point with no digits. 1.3 The third line suggests that leading zeroes are only allowed where n=d; ‘n’ is the maximum number of digits in the decimal and ‘d’ is the maximum number of digits after the decimal point. An example of why this is misleading would be if there were two data items, N123 and N456, with formats decimal (3,3) and decimal (6,3) respectively. The existing wording of the IDD would mean that values of 0.123 and .123 would be acceptable for N123, but for N456 a value of .456 would be acceptable whereas 0.456 would not. What is the issue? 1.4 This existing IDD definition is inconsistent with the examples given at the end of the definition (see above), which suggest a decimal like 0.456 should be acceptable. More importantly, this is also inconsistent with the way that the BSC Systems operate, as for any value of n and d central systems would always use the form ‘0.456’ rather than ‘.456’. 1.5 A Party identified this anomaly while testing their validation processes. ELEXON has concluded that the definition in the IDD is misleading and needs to be corrected and simplified. 2. Solution 2.1 CP1382 ‘Clarification of IDD Rules for Leading Zeroes’ was raised on 26 October 2012. The CP will amend the IDD’s definition of the decimal (n,d) data type to be consistent and clearer in its treatment of leading zeroes. 2.2 The IDD definition will be changed to state the following: maximum n digits maximum d digits after decimal point maximum (n-d) digits before decimal point leading “-” required for negative numbers no trailing zeros no leading zeros other than where -1 < value < 1, then number may start with “0.” To clarify, the value 0.123 can be represented as: 0.123 or .123, ISG140/03 – CP1382 Progression Paper Version 1.0 Page 2 of 5 © ELEXON 2012 140/03 But not: 00.123 (an invalid leading zero) or 0.1230 (an invalid trailing zero) Valid representations of zero are: 0 0.0 .0 0. -0 -0.0 -.0 -0. but not as a decimal point with no digits. 2.3 As well as being easier to understand, this avoids adding the complication of n=d (which in practice has the same impact as any value being between, but not including, -1 and 1). 2.4 You can find the full IDD redlining in Attachment A. 3. Industry views 3.1 We issued CP1381 for participant Impact Assessment via CPC00719 on 26 October 2012. We received seven responses, of which six agreed with the change and one was neutral. 3.2 The breakdown of responses is shown in the following table. You can find the full collated participant responses to CP1382 in Attachment B and on the BSC Website here. Respondent role Supports CP? Yes No Neutral Supplier/Party Agent 3 0 0 Party Agent 2 0 1 Supplier/Generator 1 0 0 Total 6 0 1 3.3 Only one respondent provided reasons for their view, stating that they support the change as it will provide additional clarity in the definition. 3.4 One of the respondents commented on an example provided in the CP1382 form, stating that “We assume that the example in the CP is incorrect, i.e. format decimal (3,3) does not gives 0.1234 and .1234 and format decimal (6,3) does not give .5678, but the principle is correct.” 3.5 ELEXON has clarified that the example given in the CP form was a demonstration of how the current definition of the decimal (n,d) data type is misleading in its treatment of leading zeroes. ISG140/03 – CP1382 Progression Paper Version 1.0 Page 3 of 5 © ELEXON 2012 140/03 Comments on the proposed redlining 3.6 We received one comment on the proposed redlining to the NETA IDD Part 1: Comments on proposed redlining Organisation Doc name Comment ELEXON’s recommendation and location EDF Energy NETA IDD Part Suggest that 'no leading zeros other ELEXON agrees that the text should 1 section 2.2.3 than where value is between -1 and 1, change from: then number may start with "0."' ‘no leading zeros other than where be changed to value is between -1 and 1, then number may start with “0”.’ 'no leading zeros other than where value is between but not including -1 To: and 1, then number may start with ‘No leading zeros other than where -1 "0."', < value <1, then number may start or with “0”.’ 'no leading zeros other than where We have advised the respondent of value is greater than -1 and less than 1, this recommended change in line with then number may start with "0."', their suggestion. or more simply: 'no leading zeros other than where -1 < value < 1, then number may start with "0."'. Otherwise, there is a possibility of, for example, "01.0", depending on human or software interpretation. 4. Intended benefits 4.1 The current IDD definition is not consistent and can be confusing in its treatment of leading zeroes; at worst it gives a misleading impression of how data is delivered by the BSC Systems. This CP proposes a change to the definition so that it is clearer, simpler and more accurately reflects how the systems operate. 4.2 Also, much of the definition is concerned with the special case where n=d. There are no such data items in the current NETA catalogue; therefore there is no need for such complexity in the IDD wording. 5. Impacts and costs 5.1 The following table summarises the ELEXON effort required to implement CP1382 and the impact on market participants: ISG140/03 – CP1382 Progression Paper Version 1.0 Page 4 of 5 © ELEXON 2012 140/03 Market participant Cost/impact Implementation time needed ELEXON £240 (1 man day of effort). 2 June 2013 Release is appropriate. (implementation) Generator/Supplier Minor costs and impacts associated with process 30 days’ lead time required. and procedure changes. 5.2 Two respondents to the Industry Impact Assessment advised that they would require 30 days’ lead time in order to implement this change and that their organisation would incur minor process changes. We requested clarification of the changes required and the associated lead times. 5.3 One of the respondents advised us that they were unable to provide any further details as the internally impacted areas did not provide it to them, and we did not receive any further information from the other respondent. 6. Implementation approach 6.1 We recommend an Implementation Date for CP1382 of 27 June 2013 as part of the June 2013 BSC Systems Release. This is the next available Release; no respondents disagreed with this date, which would allow for the 30 days’ lead time requested by respondents. 7. Recommendations 7.1 ELEXON invites the ISG to: a) AGREE the proposed amendments to the NETA IDD Part 1 (including the wording change resulting from the Industry Impact Assessment as described in Section 3.6); and b) APPROVE CP1382 for implementation on 27 June 2013, as part of the June 2013 Release. Appendices: None Attachments: Attachment A – NETA IDD Part 1 Redlining Attachment B – Collated Consultation Responses For more information, please contact: Talia Addy, Change Analyst, BSC Operations [email protected] / 020 7380 4043 ISG140/03 – CP1382 Progression Paper Version 1.0 Page 5 of 5 © ELEXON 2012 .
Load more

Recommended publications
  • Bash Guide for Beginners
    Bash Guide for Beginners Machtelt Garrels Garrels BVBA <tille wants no spam _at_ garrels dot be> Version 1.11 Last updated 20081227 Edition Bash Guide for Beginners Table of Contents Introduction.........................................................................................................................................................1 1. Why this guide?...................................................................................................................................1 2. Who should read this book?.................................................................................................................1 3. New versions, translations and availability.........................................................................................2 4. Revision History..................................................................................................................................2 5. Contributions.......................................................................................................................................3 6. Feedback..............................................................................................................................................3 7. Copyright information.........................................................................................................................3 8. What do you need?...............................................................................................................................4 9. Conventions used in this
    [Show full text]
  • L#07: PHP Date & Time
    L#07: PHP Date & Time Using Date & Time in PHP Lecture 7 March 21, 2007 ©2007, I.Sarah Al-Shareef 1 Table of Content Overview Date and Time Functions Definitions Displaying Date and Time Getting Date as Timestamp Displaying Readable Date Building Formatting String Special Formatting Characters for date() Convert from Readable to Timestamp Getting Files Dates Displaying Dates in other languages Formatting Characters for strftime() March 21, 2007 ©2007, I.Sarah Al-Shareef 2 1 L#07: PHP Date & Time Overview Date & Time Functions Function Description checkdate() Validates set of Gregorian year, month, and day values (for example, 2005, 3, 17). date_sunrise() Returns time of sunrise for a given day and location (new in PHP 5). date_sunset() Returns time of sunset for a given day and location (new in PHP 5). date() Formats a local date/time, given a Unix timestamp (for example, 1111035030000 from the introduction to this chapter) and a formatting string. getdate() Given a Unix timestamp, returns an associative array containing date and time information (defaults to current time). gettimeofday() Returns an associative array containing information about the current system time. In PHP 5.1, it is possible for this function to return a float as well. March 21, 2007 ©2007, I.Sarah Al-Shareef 3 Overview Date & Time Fun cont. Function Description gmdate() Formats a GMT/UTC date/time. Uses the same formatting characters as the date() function. gmmktime() Converts a set of GMT date/time values into a Unix timestamp (analogous to mktime()). gmstrftime() Formats a GMT/UTC date/time according to locale settings (similar to strftime() except the time used is GMT/UTC).
    [Show full text]
  • RISC-V Bitmanip Extension Document Version 0.90
    RISC-V Bitmanip Extension Document Version 0.90 Editor: Clifford Wolf Symbiotic GmbH [email protected] June 10, 2019 Contributors to all versions of the spec in alphabetical order (please contact editors to suggest corrections): Jacob Bachmeyer, Allen Baum, Alex Bradbury, Steven Braeger, Rogier Brussee, Michael Clark, Ken Dockser, Paul Donahue, Dennis Ferguson, Fabian Giesen, John Hauser, Robert Henry, Bruce Hoult, Po-wei Huang, Rex McCrary, Lee Moore, Jiˇr´ıMoravec, Samuel Neves, Markus Oberhumer, Nils Pipenbrinck, Xue Saw, Tommy Thorn, Andrew Waterman, Thomas Wicki, and Clifford Wolf. This document is released under a Creative Commons Attribution 4.0 International License. Contents 1 Introduction 1 1.1 ISA Extension Proposal Design Criteria . .1 1.2 B Extension Adoption Strategy . .2 1.3 Next steps . .2 2 RISC-V Bitmanip Extension 3 2.1 Basic bit manipulation instructions . .4 2.1.1 Count Leading/Trailing Zeros (clz, ctz)....................4 2.1.2 Count Bits Set (pcnt)...............................5 2.1.3 Logic-with-negate (andn, orn, xnor).......................5 2.1.4 Pack two XLEN/2 words in one register (pack).................6 2.1.5 Min/max instructions (min, max, minu, maxu)................7 2.1.6 Single-bit instructions (sbset, sbclr, sbinv, sbext)............8 2.1.7 Shift Ones (Left/Right) (slo, sloi, sro, sroi)...............9 2.2 Bit permutation instructions . 10 2.2.1 Rotate (Left/Right) (rol, ror, rori)..................... 10 2.2.2 Generalized Reverse (grev, grevi)....................... 11 2.2.3 Generalized Shuffleshfl ( , unshfl, shfli, unshfli).............. 14 2.3 Bit Extract/Deposit (bext, bdep)............................ 22 2.4 Carry-less multiply (clmul, clmulh, clmulr)....................
    [Show full text]
  • A Novel High Speed Leading Zero Counter for Floating Point Units
    Satish Paidi, Rohit Sreerama, K.Neelima / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 2,Mar-Apr 2012, pp.1103-1105 A Novel High Speed Leading Zero Counter For Floating Point Units Satish Paidi*, Rohit Sreerama*, K.Neelima** *(M.Tech VLSI, Sree Vidyanikethan Engineering College, Tirupathi,) ** (Assistant Professor, Sree Vidyanikethan Engineering College, Tirupathi,) ABSTRACT: - This paper mainly focuses on leading derived Boolean relations that describes the proposed zero counting. In this paper a novel leading zero counter leading zero counter. In section 4 the implementation is proposed. New Boolean expressions are derived for results and the comparison with the existing method are the new leading zero counter. We can explore various discussed and section 5 concludes the paper follows by designs of leading zero counting unit by using the the references. proposed approach. When compared with the known architectures the new circuits can be implemented II. FUNCTIONALITY OF EXISTING effectively in both static and dynamic logic and also LEADING ZERO COUNTING METHOD requires less energy per operation. The proposed leading This section discusses the method which is used in zero counter can also be integrated with a leading zero leading zero counting, their implementation and anticipation logic for better and fast results. Finally, a functionality. A leading zero is any zero bit that leads a simple and effective Leading Zero Counter was proposed number string in positional notation. In binary and the occupancy rate and the delay characteristics are representation consider the number of consecutive zeros investigated. that appear in a word before the first more significant bit Keywords - Floating Point Unit, Normalization, Leading that equal to one.
    [Show full text]
  • Leading One Prediction - Implementation, Generalization, and Application
    LEADING ONE PREDICTION - IMPLEMENTATION, GENERALIZATION, AND APPLICATION Nhon Quach Michael J. Flynn Technical Report: CSL-TR-91-463 March 1991 This work was supported by NSF contract No. MlP88-22961. Leading One Prediction - Implementation, Generalization, and Application bY Nhon Quach and Michael Flynn Technical Report: CSL-TR-91-463 Masch 1991 Computer Systems Laboratory Departments of Electrical Engineering and Computer Science St anford University St anford, California 94305 Abstract This paper presents the concept of leading-one prediction (LOP) used in most high-speed floating-point adders in greater detail and describes two existing implementations. The first one is similar to that used in the TBM RS /GO00 processor. The second is a distributed version of the first, con- suming less hardware when multiple patterns need to be detected. We show how to modify these circuits for sign-magnitude numbers as dictated by the IEEE standard. We then point out that (1) LOP and carry lookahead in parallel addition belong to the same class of problem, that of bit pattern detection. Such a recognition allows techniques developed for parallel addition to be borrowed for bit pattern detection. And (2) LOP can be applied to compute the sticky bit needed for binary multipliers to perform IEEE rounding. Key Words and Phrases: Lea,ding one prediction, high-speed floating- point adders, parallel addition, IEEE rounding, sticky bit computation, par- allel implementation. Copyright @ 1991 bY Nhon Quach and Michael Flynn Contents 1 Introduction 1 2 Leading One Prediction 2 2.1 Theory. ...................................... 2 2.2 Implementations ................................. 3 2.3 Modification for Sign-Magnitude Numbers ..................
    [Show full text]
  • The C Programming Language
    The C programming Language The C programming Language By Brian W. Kernighan and Dennis M. Ritchie. Published by Prentice-Hall in 1988 ISBN 0-13-110362-8 (paperback) ISBN 0-13-110370-9 Contents ● Preface ● Preface to the first edition ● Introduction 1. Chapter 1: A Tutorial Introduction 1. Getting Started 2. Variables and Arithmetic Expressions 3. The for statement 4. Symbolic Constants 5. Character Input and Output 1. File Copying 2. Character Counting 3. Line Counting 4. Word Counting 6. Arrays 7. Functions 8. Arguments - Call by Value 9. Character Arrays 10. External Variables and Scope 2. Chapter 2: Types, Operators and Expressions 1. Variable Names 2. Data Types and Sizes 3. Constants 4. Declarations http://freebooks.by.ru/view/CProgrammingLanguage/kandr.html (1 of 5) [5/15/2002 10:12:59 PM] The C programming Language 5. Arithmetic Operators 6. Relational and Logical Operators 7. Type Conversions 8. Increment and Decrement Operators 9. Bitwise Operators 10. Assignment Operators and Expressions 11. Conditional Expressions 12. Precedence and Order of Evaluation 3. Chapter 3: Control Flow 1. Statements and Blocks 2. If-Else 3. Else-If 4. Switch 5. Loops - While and For 6. Loops - Do-While 7. Break and Continue 8. Goto and labels 4. Chapter 4: Functions and Program Structure 1. Basics of Functions 2. Functions Returning Non-integers 3. External Variables 4. Scope Rules 5. Header Files 6. Static Variables 7. Register Variables 8. Block Structure 9. Initialization 10. Recursion 11. The C Preprocessor 1. File Inclusion 2. Macro Substitution 3. Conditional Inclusion 5. Chapter 5: Pointers and Arrays 1.
    [Show full text]
  • Computer Architectures an Overview
    Computer Architectures An Overview PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Sat, 25 Feb 2012 22:35:32 UTC Contents Articles Microarchitecture 1 x86 7 PowerPC 23 IBM POWER 33 MIPS architecture 39 SPARC 57 ARM architecture 65 DEC Alpha 80 AlphaStation 92 AlphaServer 95 Very long instruction word 103 Instruction-level parallelism 107 Explicitly parallel instruction computing 108 References Article Sources and Contributors 111 Image Sources, Licenses and Contributors 113 Article Licenses License 114 Microarchitecture 1 Microarchitecture In computer engineering, microarchitecture (sometimes abbreviated to µarch or uarch), also called computer organization, is the way a given instruction set architecture (ISA) is implemented on a processor. A given ISA may be implemented with different microarchitectures.[1] Implementations might vary due to different goals of a given design or due to shifts in technology.[2] Computer architecture is the combination of microarchitecture and instruction set design. Relation to instruction set architecture The ISA is roughly the same as the programming model of a processor as seen by an assembly language programmer or compiler writer. The ISA includes the execution model, processor registers, address and data formats among other things. The Intel Core microarchitecture microarchitecture includes the constituent parts of the processor and how these interconnect and interoperate to implement the ISA. The microarchitecture of a machine is usually represented as (more or less detailed) diagrams that describe the interconnections of the various microarchitectural elements of the machine, which may be everything from single gates and registers, to complete arithmetic logic units (ALU)s and even larger elements.
    [Show full text]
  • Decimal Fractions
    Decimal Fractions Decimal Fractions Curriculum Ready www.mathletics.com Decimalfractionsallowustobemoreaccuratewithourcalculationsandmeasurements. Becausemostofushavetenfingers,itisthoughtthatthisisthereasonthedecimalfractionsystem isbasedaroundthenumber10! Sowecanthinkofdecimalfractionsasbeingfractionswithpowersof10 inthedenominator. WriteinthisspaceEVERYTHINGyoualreadyknowaboutdecimalfractions. s a go! Give thi Q Tomakedark-greencolouredpaint,youcanmixyellowandbluetogether,usingexactly0.5(half)asmuch yellowasyoudoblue. Howmuchdark-greenpaintwillyoumakeifyouuseallofthe12.5 mLofbluepaintyouhave? Work through the book for a great way to do this Decimal Fractions H 6 1 Mathletics Passport © 3P Learning SERIES TOPIC How does it work? Decimal Fractions Place value of decimal fractions Decimalfractionsrepresentpartsofawholenumberorobject. thousandths thousands of • thousandths Millionths Tens ThousandsHundredsTens Ones TenthsHundredthsThousandthsTen HundredMillionthsTen W H O L E D E C I M A L 1 10 10 # 000 000 000 000 000 100 100 # ' 1000 1000 # ' # Decimalpoint 10 10 ' 000 000 # 100 ' 1 ' 10 ' ' st 1 1 decimalplace:'10 ==# onetenth 10 nd 1 2 decimalplace:'10 ==# onehundredth 100 Add‘th’tothe namefordecimal rd 1 3 decimalplace:'10 ==# onethousandth placevalues 1000 th 1 4 decimalplace:'10 ==# onetenthousandth etc... 10 000 Writetheplacevalueofeachdigitinthenumber465.2703 4 6 5 . 2 7 0 3 Multiplybymultiplesof 10 Dividebymultiplesof 10 Expanded forms Place values 4......41# 00 = 400 = 4hundred 6......61# 0 = 60 = 6tens(orsixty) Integerparts
    [Show full text]
  • Programming in C
    Programming in C Programming in C This is a set of notes on Programming in C. They were originally prepared as plain ASCII files using a private set of nroff macros and have now been converted to HTML. Most of the small programming examples are available on-line. Just select the link about the program and then use your WWW browser's ability to save pages in a local file. 1. Chapter 1 Introduction 2. Chapter 2 Programming with Integers 3. Chapter 3 Arithmetic 4. Chapter 4 Data Types 5. Chapter 5 Loops and Conditions 6. Chapter 6 Addresses, Arrays, Pointers and Strings 7. Chapter 7 Functions and Storage Management 8. Chapter 8 The Pre-Processor and Standard Libraries 9. Chapter 9 Command Line Arguments and File Handling 10. Chapter 10 Structures, Unions and Typedefs 11. Chapter 11 Separate Compilation of C Modules 12. Chapter 12 Efficiency, Economy and Portability There are various other sources of information available on-line. If you are really interested in the C programming language you should 1. Read the comp.lang.c newsgroup 2. Obtain and read the comp.lang.c FAQ 3. Study the submissions to the International Obfuscated C Code Contest If you are interested in systems programming especially in the Unix context there are further notes on a wide range of topics. Peter Burden [email protected] http://www.scit.wlv.ac.uk/~jphb/cbook/html/ [02/04/2002 09:18:37] Introduction to C Programming - Introduction Introduction to C Programming - Introduction Chapter chap1 section 1 By time-honoured convention the first C program anybody writes is known as the "hello world" program.
    [Show full text]
  • Bits and Bit Sequences Integers
    Data ● (Some repeating CS1083, ECE course) ● bits and bit sequences ● integers (signed and unsigned) ● bit vectors ● strings and characters ● floating point numbers ● hexadecimal and octal notations Bits and Bit Sequences ● Fundamentally, we have the binary digit, 0 or 1. ● More interesting forms of data can be encoded into a bit sequence. ● 00100 = “drop the secret package by the park entrance” 00111 = “Keel Meester Bond” ● A given bit sequence has no meaning unless you know how it has been encoded. ● Common things to encode: integers, doubles, chars. And machine instructions. Encoding things in bit sequences (From textbook) ● Floats ● Machine Instructions How Many Bit Patterns? ● With k bits, you can have 2k different patterns ● 00..00, 00..01, 00..10, … , 11..10, 11..11 ● Remember this! It explains much... ● E.g., if you represent numbers with 8 bits, you can represent only 256 different numbers. Names for Groups of Bits ● nibble or nybble: 4 bits ● octet: 8 bits, always. Seems pedantic. ● byte: 8 bits except with some legacy systems. In this course, byte == octet. ● after that, it gets fuzzy (platform dependent). For 32-bit ARM, – halfword: 16 bits – word: 32 bits Unsigned Binary (review) ● We can encode non-negative integers in unsigned binary. (base 2) ● 10110 = 1*24 + 0*23 + 1*22 + 1*21 +1*20 represents the mathematical concept of “twenty-two”. In decimal, this same concept is written as 22 = 2*101 + 2*100. ● Converting binary to decimal is just a matter of adding up powers of 2, and writing the result in decimal. ● Going from decimal to binary is trickier.
    [Show full text]
  • Avoiding Decimal Errors—November 2006
    MEDICATION SAFETY Avoiding Decimal Errors umbers containing decimal points on computer generated labels. A newly admitted hospital are a major source of error and when patient told her physician that she took phenobarbital 400 misplaced, can lead to misinterpreta- mg three times daily. Subsequently, the physician wrote an tion of prescriptions. Decimal points order for the drug in the dose relayed by the patient. A nurse can be easily overlooked, especially saw the prescription vial and verified that this was the correct on prescriptions that have been faxed, dose. However, prior to dispensing, a hospital pharmacist prepared on lined order sheets or prescription investigated the unusually high dose. When he checked the Npads, or written or typed on carbon and no-car- prescription vial, he found that it was labeled as “PHENO- bon-required (NCR) forms. If a decimal point is BARBITAL 32.400MG TABLET” (see graphic). missed, an overdose may occur. The importance To avoid misinterpretations due to decimal point place- of proper decimal point placement and promi- ment, health care practitioners should consider the following: nence cannot be overstated. • Always include a leading zero for dosage strengths or A decimal point should always be preceded concentrations less than one. by a whole number and never be left “naked.” • Never follow a whole number with a decimal point and a Decimal expressions of numbers less than one zero or multiple zeroes (trailing zero). should always be preceded by a zero (0) to en- • Eliminate dangerous decimal dose expressions from hance the visibility of the decimal. For example, pharmacy and prescriber electronic order entry screens, computer-generated labels, and preprinted prescriptions.
    [Show full text]
  • Safe Prescribing
    Special issue PRESCRIBING THE ROLE OF SAFE PRESCRIBING IN THE PREVENTION OF MEDICATION ERRORS edications are the most common cause order is written, flag the patient’s chart and place it in the of adverse events in hospitalized rack by the clerical associate to ensure that the nurse and M patients.1,2 Adverse drug events (ADEs) the pharmacist are aware of the order. This process is occur during 6.5% of hospital admissions and 1% essential because the omission of medication of patients suffer disabling injuries as a result of an administration, usually first time doses, is the most ADE.1,2,3 Common causes of medication errors are frequently reported medication error type at Shands listed in Table 1.4 Because adverse Jacksonville. reactions to medications can be Obviously, no one group of serious or fatal, it is extremely " Preventing medication healthcare professionals is responsible for important that drug allergies and errors must be a multi- all errors. Therefore, preventing the reactions are documented. medication errors must be a multi- Additionally, medications can be disciplinary effort." disciplinary effort. For any further easily confused as a result of look- questions, please contact your liaison alike or sound-alike names and pharmacist or the Drug Information abbreviations (e.g., Toradol and tramadol, O.D. Service at 244-4185. can be interpreted as once daily or right eye, and (Continued on page 2) AZT could represent azathioprine or zidovudine). It is important that everyone utilize strategies to Table 1. Common Causes of Medication Errors decrease medication errors. Several tips for safe prescribing of medications are reviewed in Table 2 and should be incorporated into daily practice.4 • Ambiguous strength designation When writing orders for patients in the • Look-alike or sound-alike names or use of hospital, the same tips are useful.
    [Show full text]