1、Juni 2013DEUTSCHE NORM DKE Deutsche Kommission Elektrotechnik Elektronik Informationstechnik im DIN und VDEPreisgruppe 13DIN Deutsches Institut fr Normung e. V. Jede Art der Vervielfltigung, auch auszugsweise, nur mit Genehmigung des DIN Deutsches Institut fr Normung e. V., Berlin, gestattet.ICS 35.
2、110!$Tk“1974972www.din.deDDIN EN 62439-1/A1Industrielle Kommunikationsnetze Hochverfgbare Automatisierungsnetze Teil 1: Grundlagen und Berechnungsmethoden(IEC 62439-1:2010/A1:2012);Englische Fassung EN 62439-1:2010/A1:2012Industrial communication networks High availability automation networks Part 1
3、: General concepts and calculation methods (IEC 62439-1:2010/A1:2012);English version EN 62439-1:2010/A1:2012Rseaux de communication industriels Rseaux de haute disponibilit pour lautomatisation Partie 1: Concepts gnraux et mthodes de calcul (CEI 62439-1:2010/A1:2012);Version anglaise EN 62439-1:201
4、0/A1:2012Alleinverkauf der Normen durch Beuth Verlag GmbH, 10772 Berlinnderung vonDIN EN 62439-1:2010-09Siehe Anwendungsbeginnwww.beuth.deGesamtumfang 16 SeitenDIN EN 62439-1/A1:2013-06 2 Anwendungsbeginn Anwendungsbeginn fr die von CENELEC am 2012-07-19 angenommene nderung A1 als DIN-Norm ist 2013-
5、06-01. Fr DIN EN 62439-1:2010-09 besteht eine bergangsfrist bis 2015-07-19. Nationales Vorwort Vorausgegangener Norm-Entwurf: E DIN EN 62439-1/A1:2011-08. Fr dieses Dokument ist das nationale Arbeitsgremium K 956 Feldbus“ der DKE Deutsche Kommission Elektrotechnik Elektronik Informationstechnik im D
6、IN und VDE (www.dke.de) zustndig. Die enthaltene IEC-Publikation wurde vom SC 65C Industrial networks“ erarbeitet. Das IEC-Komitee hat entschieden, dass der Inhalt dieser Publikation bis zu dem Datum (stability date) unverndert bleiben soll, das auf der IEC-Website unter http:/webstore.iec.ch“ zu di
7、eser Publikation angegeben ist. Zu diesem Zeitpunkt wird entsprechend der Entscheidung des Komitees die Publikation besttigt, zurckgezogen, durch eine Folgeausgabe ersetzt oder gendert. Fr den Fall einer undatierten Verweisung im normativen Text (Verweisung auf eine Norm ohne Angabe des Ausgabedatum
8、s und ohne Hinweis auf eine Abschnittsnummer, eine Tabelle, ein Bild usw.) bezieht sich die Verweisung auf die jeweils neueste gltige Ausgabe der in Bezug genommenen Norm. Fr den Fall einer datierten Verweisung im normativen Text bezieht sich die Verweisung immer auf die in Bezug genommene Ausgabe d
9、er Norm. Der Zusammenhang der zitierten Normen mit den entsprechenden Deutschen Normen ergibt sich, soweit ein Zusammenhang besteht, grundstzlich ber die Nummer der entsprechenden IEC-Publikation. Beispiel: IEC 60068 ist als EN 60068 als Europische Norm durch CENELEC bernommen und als DIN EN 60068 i
10、ns Deutsche Normenwerk aufgenommen. Das Prsidium des DIN hat mit Prsidialbeschluss 1/2004 festgelegt, dass DIN-Normen, deren Inhalt sich auf internationale Arbeitsergebnisse der Informationsverarbeitung grndet, unter bestimmten Bedingungen allein in englischer Sprache verffentlicht werden drfen. Die
11、se Bedingungen sind fr die vorliegende Norm erfllt. Da sich die Benutzer der vorliegenden Norm der englischen Sprache als Fachsprache bedienen, wird die englische Fassung der EN 62439-1/A1 verffentlicht. Zu deren Abschnitt 3, der die Begriffe festlegt, wurde eine bersetzung angefertigt und als infor
12、mativer Nationaler Anhang NA der vorliegenden Norm hinzugefgt. Fr viele der verwendeten Begriffe existieren keine gebruchlichen deutschen Benennungen, da sich die deutschen Anwender in der Regel ebenfalls der englischen Benennungen bedienen. Diese Norm steht nicht in unmittelbarem Zusammenhang mit R
13、echtsvorschriften und ist nicht als Sicherheitsnorm anzusehen. DIN EN 62439-1/A1:2013-06 3 Nationaler Anhang NA (informativ) 3.1 Begriffe Fgen Sie die folgenden neuen Begriffe 3.1.67 und 3.1.68 hinzu: 3.1.67 Netzwerkbrcke (en: bridge) Gert, das zwei Segmente eines Netzwerks (LAN“) auf der Sicherungs
14、schicht (Layer 2“) gem IEEE 802.1D miteinander verbindet ANMERKUNG Die Begriffe Netzwerkweiche (en: switch)“ und Netzwerkbrcke (en: bridge)“ werden synonym verwendet. Der Begriff Netzkwerkbrcke“ ist im Kontext verschiedener Spezifikationen gebruchlich, beispielsweise RSTP (IEEE 802.1D), PTP (IEC 615
15、88) oder IEC 62439-3 (PRP 35.100.01 English version Industrial communication networks - High availability automation networks - Part 1: General concepts and calculation methods (IEC 62439-1:2010/A1:2012) Rseaux de communication industriels - Rseaux de haute disponibilit pour lautomatisation - Partie
16、 1: Concepts gnraux et mthodes de calcul (CEI 62439-1:2010/A1:2012) Industrielle Kommunikationsnetze - Hochverfgbare Automatisierungsnetze - Teil 1: Grundlagen und Berechnungsmethoden (IEC 62439-1:2010/A1:2012) This amendment A1 modifies the European Standard EN 62439-1:2010; it was approved by CENE
17、LEC on 2012-07-19. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may b
18、e obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This amendment exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to
19、the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
20、Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. EN 62439-1:2010/A1:2012 - 2 - Foreword The text of document 65C/684/FDIS, future edition 1 of IEC
21、 62439-1:2010/A1, prepared by SC 65C, “Industrial networks“, of IEC TC 65, “Industrial-process measurement, control and automation“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62439-1:2010/A1:2012. The following dates are fixed: latest date by which the document has
22、to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2013-04-19 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2015-07-19 Attention is drawn to the possibility that some of the elements of t
23、his document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 62439-1:2010/A1:2012 was approved by CENELEC as a European Standard without any modification
24、. Add to the Bibliography of EN 62439-1:2010, the following note for the standard indicated: IEC 62439-7 NOTE Harmonized as EN 62439-7. 2 62439-1 Amend. 1 IEC:2012 FOREWORD This amendment has been prepared by subcommittee 65C: Industrial networks, of IEC technical committee 65: Industrial-process me
25、asurement, control and automation, working group 15. The text of this amendment is based on the following documents: FDIS Report on voting 65C/684/FDIS 65C/691/RVD Full information on the voting for the approval of this amendment can be found in the report on voting indicated in the above table. The
26、 committee has decided that the contents of this amendment and the base publication will remain unchanged until the stability date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn
27、, replaced by a revised edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer. _
28、 3.1 Terms and definitions Add the following new terms and definitions 3.1.67 and 3.1.68: 3.1.67 bridge device connecting LAN segments at layer 2 according to IEEE 802.1D NOTE The words “switch” and “bridge” are considered synonyms, the word “bridge” is used in the context of standards such as RSTP
29、(IEEE 802.1D), PTP (IEC 61588) or IEC 62439-3 (PRP “N” is the number of bridges in the main ring (excluding the bridges that connect the sub-rings); “M” is the number of bridges in the main ring that connect the main ring to the sub-rings. In the diagram above, considering that N=3, M=2, R=4, the wo
30、rst case radius = 11. Thus, the RSTP protocol parameter “Bridge Max Age” should be configured to a value of 10 to optimize network recovery times. 8.5.7 Worst case radius of an optimized multilayer architecture With a large number of bridges, the network topology should be optimized in order not to
31、reach the Bridge Max Age limit and to keep worst case reconfiguration times low. 62439-1 Amend. 1 IEC:2012 9 A simple solution is to consider a multilayer topology, consisting of “L” layers, as shown in Figure 26: IEC 957/12 Figure 26 Example multilayer topology The upper layer is made of 2 main bri
32、dges which are set to be the root/backup root bridges. (Priority value of these bridges is expected to be set consequently to the highest and second to highest priority). The maximum size of layer 3 is defined by sub-rings made of “R” bridges. The parameter “R” excludes the bridges that connect the
33、individual layer 3 subring to layer 2, which is taken into the calculation through the parameter “L”. Only one failure per layer is considered. Then the worst case radius is equal to: worst case radius = (2 L) + R In the above diagram, L=3, R=4, and therefore, worst case radius = 10. This results in
34、 a Bridge Max Age parameter of 9. The interesting point is that this result is not dependant on the number of branch-offs per layers, and this topology is possibly able to support a large number of nodes with a low Bridge Max Age parameter. The limitation is the maximum number of ports of the bridge
35、s used at each layer: A large number of physical ports is detrimental to RSTP performance on bridges. 8.5.8 Approximated upper bond reconfiguration time for RSTP networks The RSTP root bridge failure is the worst case scenario aftecting reconfiguration time. The upper bond reconfiguration time is th
36、e time needed for recovery after a root bridge failure. The recovery time for link failures or non-root bridge failures will not exceed the root bridge 10 62439-1 Amend. 1 IEC:2012 failure recovery time. Since it is the worst case scenario, the recovery time subsequently is estimated for a root brid
37、ge failure. When considering the network reconfiguration time of a meshed RSTP network, three distinct phases can be identified: Aging phase: The phase in which the fault in the network is detected and in which multiple root information (old and new root priority vectors) are still present in the ne
38、twork. The old root information can still circulate around in the network until the Message Age in the BPDUs reaches the Bridge Max Age value. Only after the old root priority vector from the failed root bridge has been completely eliminated from the network, can the backup root priority vector prev
39、ail. The aging phase is therefore the time from the fault to the moment, when the old root BPDU priority vector is eliminated and, in a worst case situation, any other, inferior new temporary root vector reaches the backup root bridge and triggers the converging phase. Converging phase: The phase in
40、 which the backup root broadcasts its new root vector to the network and is no longer disturbed by old root vector information. The converging phase immediately starts after the aging phase and ends when the bridge farthest away from the new backup root has received the new root information. Flushin
41、g phase: After the reconfiguration of the active topology, several bridges could flush their filtering databases to make certain that the new communication paths are learned properly. RSTP uses Topology Change (TC) BPDUs to initiate flushing. With a worst case assumption, this phase begins immediate
42、ly after the converging phase and ends after the Topology Change notification from the bridge farthest away from the root has reached the root bridge. NOTE When a root bridge fails, usually more than one bridge claims root. But as the backup root has the best remaining priority, its priority vector
43、quickly (one single priority propagation through the topology) prevails against the other temporary root bridges. But in a worst case scenario, the better priority vector from the old root may still “circulate” around much longer. This is, therefore, the limiting element that defines the length of t
44、he aging phase. The total upper bond reconfiguration time Trec of a meshed RSTP network can therefore be approximated as: Trec = TL + Tage + Tconv + Tflush where: Tage = 2 Bridge Max Age TPA; Tconv = worst case radius TPA; Tflush = worst case radius TTC; TL is the maximum time required by a bridge t
45、o detect a link failure (depends on the link type); TPA is the maximum time required by a pair of bridges to perform RSTP Proposal Agreement handshaking; equal to the sum of the BPDU processing times in both bridges of the pair. TPA values may differ from vendor to vendor and from product to product
46、; TTC is the time an Ethernet bridge needs to process an RSTP topology change. Typical values for “fast RSTP” implementation: TPA = 5 ms when the vendor claims a 5 ms/hop recovery time TL = 4-6 ms for 100BASE-TX and 100BASE-FX links = 20 ms for 1000BASE-X links = 700 ms for 1000BASE-T links (defined
47、 by the ISO/IEC 8802-3) 62439-1 Amend. 1 IEC:2012 11 This approximation shows that it is beneficial for the total recovery time to set the Bridge Max Age parameter as high as necessary to support the given topology (with respect to possible failures), but as low as possible to minimize its impact on
48、 the network recovery time. This approximation of recovery time covers the worst case scenario, the root bridge failure. When comparing the likeliness of a root bridge failure to the likeliness of a non-root or link failure, a root bridge failure is far more unlikely (when similar failure probabilit
49、ies for all participating devices and media are assumed) because for each root bridge there is a large number of media connections and non-root bridges that may fail before. Therefore, the typical recovery time will be faster than the worst case recovery time that can be approximated by this clause, but this cannot be counted on. NOTE There may be an additional effect when a bridge with multiple ports connected to the RSTP network is be
