WELMEC 10.10 2016 Guide n evaluatin f Purely Digital Parts
WELMEC is a cperatin between the legal metrlgy authrities f the Member States f the Eurpean Unin and EFTA. This dcument is ne f a number f Guides published by WELMEC t prvide guidance t manufacturers f measuring instruments and t Ntified Bdies respnsible fr cnfrmity assessment f their prducts. The Guides are purely advisry and d nt themselves impse any restrictins r additinal technical requirements beynd thse cntained in relevant EU Directives. Alternative appraches may be acceptable, but the guidance prvided in this dcument represents the cnsidered view f WELMEC as t the best practice t be fllwed. Published by: WELMEC Secretariat E-mail: secretary@welmec.rg Website: www.welmec.rg Page 2 f 13
Cntents 1 Intrductin... 4 2 Scpe... 5 3 Definitins, abbreviatins and symbls... 7 4 Special cases f purely digital parts... 8 4.1 Cmbinatins... 8 4.2 Simple recipient printer... 8 4.3 SSD... 8 5 Evaluatin prcedure f the PDP... 9 5.1 Applicatin... 9 5.2 Test requirements... 9 5.3 Evaluatin... 10 6 Certificates... 12 6.1 EC r PC... 12 6.2 TEC... 12 6.3 Revisin f certificates... 13 Page 3 f 13
1 Intrductin Measuring systems fr liquids ther than water (MI) are ften cnstructed frm typical parts, such as gas separatrs, measurement transducers, electrnic calculating / indicating devices, cnversin devices and ancillary devices, prduced by different Original Equipment Manufacturers (OEMs), in this dcument referred t as prducers. This dcument prvides guidance n the evaluatin f purely digital parts f a measuring system. Nte: WELMEC guide 8.8 prvides guidance n the general and administrative aspects f the vluntary system f mdular evaluatin f a measuring instrument. Page 4 f 13
2 Scpe This guide cvers devices as specified by OIML R117-1, editin 2007 and purely digital parts as specified by this guide; bth categries are named purely digital parts hereafter. This guide nly cvers separate purely digital parts used in measuring instruments fr liquids ther than water. By separate is meant that the part under evaluatin has its wn husing and pwer supply. By purely digital is meant that the electrnic part nly perfrms digital functins and prvides a digitized utput r display. The fact that the purely digital part shuld nly perfrm digital functins means that the part des nt have analgue inputs and des nt include time dependant data acquisitin fr the measurement and thus that the discnnectin f the part during the measurement des nt impact the measurement results. The fact that discnnectin f the part shuld nt impact the measurement results means that the necessary checking facilities shuld ensure that: any failure, stp, pwer interrupt r accident will make sftware resuming rutine t check that any engaged actin befre such event had the expected terminatin it was seeking, r that n further actin will be allwed t take place till remedy has been brught; data chain integrity is secured by making sure that any infrmatin used upstream by a sftware mdule is kept retrievable till prper cmpletin f expected actins engaged by the sftware mdule. The purely digital part can nly be evaluated accrding t this guide under the fllwing cnditins: The part is defined in OIML R117-1, editin 2007 and there exist requirements fr this part in this guide, r the relevant requirements f OIML R117-1, editin 2007 can be applied t the part; The hardware f the part bears the CE-mark accrding t at least the EMC directive. If during evaluatin it is established that nt all f the checking facilities are present then an EC r PC under this guide cannt be issued. Even if mdular evaluatin is used, the manufacturer shall apply fr a cnfrmity assessment prcedure fr the cmplete measuring instrument. It shuld be nted that it is the respnsibility f the manufacturer f the cmplete instrument t be able t demnstrate the cnfrmity t all applicable requirements f the MID even in case the mdular evaluatin is used. The part shall bear the CE marking accrding t Eurpean directives ther than the MID and the EC r PC number, but it cannt bear the supplementary metrlgy marking and Ntified Bdy number relating t the MID. Page 5 f 13
Only a cmplete measuring instrument (r sub-assembly if freseen in the MID) may bear the supplementary metrlgy marking and Ntified Bdy number relating t the declaratin f cnfrmity t the MID. Page 6 f 13
3 Definitins, abbreviatins and symbls The definitins f OIML R117-1, editin 2007 apply t this guide tgether with the definitins given in WELMEC guide 8.8. Abbreviatins: MI Measuring instrument fr liquids ther than water (under MI-005 f the MID) Part A part f a MI which perfrms a specific functin and can be evaluated separately. This als includes devices, mdules, sftware and peripherals, fr example but nt limited t: printers, data strage devices and persnal cmputers PDP Purely Digital Part SSD Self-service device(s), a SSD can be a particular PDP MID MID, directive 2004/22/EC f the Eurpean parliament and f the cuncil f 31 March 2004 n measuring instruments NB Ntified Bdy TEC Type- r Design examinatin certificate EC Evaluatin Certificate as defined in WELMEC guide 8.8 PC Parts Certificate as defined in WELMEC guide 8.8 R117-1 OIML R117-1, editin 2007 Page 7 f 13
4 Special cases f purely digital parts 4.1 Cmbinatins The device f a measuring system fr liquids ther than water culd, n request f the prducer and/r the manufacturer, be separated in an analgue and time dependant part and a digital part prvided that bth the analgue and time dependant part and the digital part perfrm a specific functin and d nt share the pwer-supply r husing and can be evaluated separately. Fr example the cnversin device culd be separated int analgue and time dependant part, namely the assciated measuring instruments which give a digital utput (fr example: average temperature), and a digital part, namely the PC with sftware that cnvert the actual measurement value int a cnverted value. Tgether, the assciated measuring instruments with the PC make up the cnversin device as defined under T.c.4 f OIML R117, Editin 2007. Fr example the calculatr culd be separated int an analgue and time dependant metering calculatr with a digital utput and a purely digital peratinal calculatr that prcess the digital utputs f the metering calculatr, stres the results in memry until they are used. Tgether, the metering calculatr part and the peratinal calculatr part make up the Calculatr as defined under T.c.1 4 f OIML R117, Editin 2007. Other cmbinatins are pssible prvided the cnditins abve are met. 4.2 Simple recipient printer By exceptin, any simple recipient printing device that: bears the CE marking f cnfrmity t the applicable directives, i.e. EMC and LV directive, and is nt capable f transmitting any data r instructins twards the MI, SSD r PDP ther than t release a printut r t check fr crrect data transmissin, and cannt mdify r further prcess the measuring result ther than needed t prduce a print-ut, and cmplies with the applicable requirements f article 3.4 and 4.3.5 f OIML R117-1, editin 2007 may be cnnected t a MI, SSD r PDP withut a EC r PC prvided that a statement t that extent is included in the TEC. 4.3 SSD Special deviatins f technical requirements frm R117-1 are allwed fr SSD: see 5.2.2.1. Page 8 f 13
5 Evaluatin prcedure f the PDP Fr evaluatin the fllwing prcedure shuld be fllwed. 5.1 Applicatin There shall be a written applicatin frm the prducer f the PDP fr an EC r PC. The applicatin shall cntain the fllwing: Prducers name and address; A declaratin that the PDP cannt be disturbed r fraudulently manipulated thrugh its interfaces ; A declaratin that the prducer is aware f his bligatins as specified in WELMEC guide 8.8, specifically related t the availability f the technical dcumentatin; Cmplete technical dcumentatin in accrdance with article 10 f the MID, fr example but nt limited t: General descriptin f type, and explanatins necessary t understand the functining f the PDP; Manufacturing prcedures t ensure cnsistent prductin; List f descriptins and characteristic data f all cmpnents, such as but nt limited t: Interfaces; Indicating devices; Printing devices; Data strage devices. List and descriptin f the checking facilities f the PDP; Sftware descriptin, cmmunicatin prtcls, means fr securing the sftware; Infrmatin cncerning special cases, such as but nt limited t: Special perating cnditins; Reactin f the PDP t significant faults; Functining f the PDP after switch n. A declaratin f cnfrmity stating that the hardware f the PDP cmplies with the relevant parts f the applicable directives, in particular with the EMC directive. 5.2 Test requirements 5.2.1 Requirement cncerning the technical dcumentatin The technical dcumentatin shall be in accrdance with article 10 f the MID. 5.2.2 Technical requirements The PDP shall cmply with the technical requirements, where applicable, accrding t R117-1 unless satisfying the allwed deviatins frm R117-1 as given belw. Allwed deviatin frm OIML R117-1: see 5.10.3.1.1. SSD s fr unattended delivery need t be equipped with at least ne f the fllwing: a printing device fr the cnsumer and a memry device fr the vendr, r a memry device fr the benefit f bth parties. In the case f a memry device hwever, a durable prf f the measurement result and the infrmatin t identify the transactin shall be available n request at the time the measurement is cncluded. Typically the durable prf is a printut. Page 9 f 13
In accrdance with article 10 and 11 f Annex 1 f the MID, by which the fllwing data are printed and recrded: identificatin f the measuring system, measurement data, time and date f delivery and if applicable the ID f the custmer in the case f a delayed payment. Nte: This sectin is nt intended t allw electrnic tickets as the nly durable prf. Fr that tpic specific guidance will need t be develped. The memry acts as the decisive registratin. The applicable Certificate shall clearly describe the cnfiguratin and functins f the SSD. 5.2.3 Requirements cncerning sftware The legally relevant sftware running n the PDP shall be tested in accrdance with WELMEC guide 7.2: Sftware Guide (Measuring Instruments Directive 2004/22/EC). With respect t the checking facilities, article 4.3.5 f R117-1 applies. With regard t acting upn significant fault the necessary checking facilities shuld ensure that any failure, stp, pwer interrupt r accident will make sftware resuming rutine t check that any engaged actin befre such event had the expected terminatin it was seeking, r that n further actin will be allwed t take place till remedy has been brught. data chain integrity is secured by making sure that any infrmatin used upstream by a sftware mdule is kept retrievable till prper cmpletin f expected actins engaged by the sftware mdule. Fr the sftware requirements, risk class C applies. In the case that the PDP is nt equipped with a display, the sftware identificatin shuld be transmitted t a device r part under legal cntrl that has a display and can indicate the sftware identificatin n request. 5.2.4 Requirements cncerning markings The PDP shuld either be inscribed with the fllwing markings r these marking shuld be permanently visible in the display r a cmbinatin f bth: EC r PC number f the device Prducers identificatin mark, trademark r name Type designatin Year f manufacture Serial number Identificatin f the cnnected fuel dispenser(s) if applicable The EC shuld state the psitin f the markings r refer t drawings that indicate the psitin. 5.3 Evaluatin The test institute that can als act as a Ntified Bdy under the MID fr Cnfrmity Assessment Annex B fr MI-005 shuld evaluate whether the dcumentatin is cnfirmed t be in accrdance with article 10 f the MID; Page 10 f 13
the PDP is cnfirmed t be cnstructed in accrdance with the dcumentatin, in particular if the PDP is equipped, when applicable, with a clearly readable display, a prperly perating legally relevant sftware, and the necessary checking facilities; the PDP is cnfirmed t be in accrdance with the test requirements. If the PDP has a CE marking mark f cnfrmity t at least the requirement(s) f the EMC directive, des nt include the pwer supply fr the MI and is equipped with the necessary checking facilities, under this guide n tests need t be perfrmed n the hardware f the PDP except when thse tests are needed t fulfill the checks in the checklist. In the case where the PDP is fitted with a printing device, it shall be pssible during the evaluatin t ensure that the checking facility f the printing device is functining by an actin that frces a printing malfunctin. This actin shuld be a simulated incrrectness in the generatin, transmissin (taking int accunt R117-1, 4.3.2.1), prcessing, r indicatin f measurement data but als data link cut, missing paper and pwer supply cut. In the case where the PDP is fitted with memry strage devices t stre measurement results until their use r t keep a recrd f cmmercial transactins, prviding prf in the event f a dispute, all f the memry strage devices shall be fitted with checking facilities. The aim f the checking facilities is t ensure that stred data crrespnds t the data prvided by the calculatr and that restred data crrespnds t stred data. The crrect functining f the checking facilities may be tested by means f simulatin. 5.3.1 Set-up fr evaluatin Fr evaluatin the PDP sftware may be run n the PDP r n a cmputer platfrm which is in cnfrmity t the relevant directives, in particular the requirement(s) f the EMC directive, and shall be cnnected, thrugh an apprpriate interface, t either: a simulatr; r a cmplete MI; r a cmbinatin f a simulatr and parts f a MI. Nte: It shall be ensured that in the test set-up, all functinalities have been catered fr. In the case f a SSD fr example but nt limited t price display, price runding and sales stacking during attended pst-payment, prepayment in attended mde, delayed payment and prepayment in unattended mde. If the PDP has n display then means shall be prvided t indicate the necessary data, infrmatin and results n a separate device. 5.3.2 Evaluatin reprt The test institute that can als act as a Ntified Bdy under the MID fr Cnfrmity Assessment Annex B fr MI-005 shuld issue an Evaluatin Reprt (ER) that specifies the examinatins and tests that have been perfrmed and what the utcme f the examinatins and tests were. If the PDP cmplies with all the applicable requirements f this guide an EC r PC can be issued. Page 11 f 13
6 Certificates 6.1 EC r PC The EC r PC shuld be in cmpliance with WELMEC guide 8.8. In particular the EC r PC shuld cntain: a descriptin f the legally relevant characteristics f the PDP, including its cmpatibility with ther devices r parts, and a descriptin hw the sftware identificatin can be btained and a descriptin f the sealing prvisins and in case f sftware securing, hw t check this and dcumentatin that allws the cnfrmity f the PDP including the sftware t be checked and A reference t the test reprt with the appertaining test data. A reference t this guide and WELMEC 7.2, and if apprpriate a statement that the sftware can be implemented in any CE-marked hardware. 6.2 TEC There are tw administrative ways fr including a PDP in the TEC: 1. All references and cmplete descriptin f a specific type f PDP are included in the TEC f the measuring instrument, r 2. The mdular apprach is used t allw the pssibility f using a PDP with an EC r PC by making reference t that EC r PC with the pssibility f a general statement cncerning the cnnectin f any PDP with a PC, Optin 2 is nly pssible in case the EC r PC are issued by a test institute that can als act as a Ntified Bdy under mdule B f the MID fr measuring instruments fr liquids ther than water (MI-005). A general statement in the TEC cncerning the cnnectin f any PDP evaluated under this guide, with a PC, t a MI is nly pssible if all f the fllwing cnditins are met: 1. The interfaces and prtcls f the MI are cmpatible with the interfaces and prtcls f the PDP and 2. The MI shall transmit data relating t presentatin f results nly in such a manner that the PDP can meet the requirements and 3. The cnnectin t the PDP shall nt allw the metrlgical functins f the MI t be inadmissibly influenced by r thrugh the PDP and 4. The cnnectin f the PDP shall nt lead t an instrument having metrlgical characteristics ther than thse specified in the TEC fr the MI. 6.2.1 Wrding in the TEC f the MI The manufacturer f the MI, in the applicatin fr type-examinatin, shall request the pssibility f cnnecting any PDP evaluated under this guide, t his MI. If the manufacturer requests a general statement fr the cnnectin f any PDP evaluated under this guide with a PC, the fllwing cnditins shuld be stated in the TEC: The PDP has a PC issued by a test institute that can als act as a Ntified Bdy under mdule B f the MID fr measuring instruments fr liquids ther than water (MI-005); Page 12 f 13
The cnnectin shall be made in such a way that the presentatin f the results meets the essential requirements f the MID; and The cnnectin shall be made thrugh the interfaces with the specified prtcls as mentined in the TEC, and/r the PC. With regard t a simple recipient printer the fllwing shuld be stated in the TEC (see 4.2 abve): Any simple recipient printing device may be cnnected t the measuring instrument prvided that the simple recipient printer: bears the CE marking f cnfrmity t the applicable directives, i.e. EMC and LV directive, and is nt capable f transmitting any data r instructins twards the MI, SSD r PDP r any part ther than t release a printut r t check fr crrect data transmissin, and cannt mdify r further prcess the measuring result ther than needed t prduce a print-ut, and cmplies with the applicable requirements f article 3.4 and 4.3.5 f OIML R117-1, editin 2007. 6.3 Revisin f certificates The applicant shall keep the ntified bdy that has issued the TEC r EC r PC infrmed f all mdificatins t the instrument that may affect the cnfrmity f the instrument with the (essential) requirements r the cnditins fr validity f the certificate. Where such changes influence cnfrmity with the essential requirements r the prescribed cnditins fr use f the instrument an additin t the TEC r revisin f the EC r PC is necessary. Mdificatin f the existing sftware, i.e. bug fixes and r security patches, nt already cvered by the certificate can be handled by an additin t the TEC r revisin f the EC r PC. In any case the certificate shuld state the nature f the bug fix r security patch. Adding functinality t the existing sftware can be handled by an additin t the TEC r revisin f the EC r PC. In any case the certificate shuld state which functinality is added t the existing sftware. In case the essential parts f the sftware are rewritten a new certificate shuld be issued. Page 13 f 13