Configurations for Communication Communication with Automation Systems Planning - Configuring - Referencing Communication with Automation Systems Rev. A - Endgültig 12.04.2004 2/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Preamble Introduction Nowadays, the communication possibilities between automation systems are a core demand and necessity, even in the case of systems of the lower performance class. Due to the large variety of communication processors, protocols and user interfaces in the SIMATIC homogenous system world (i.e. only SIMATIC systems communicate with each other) and particularly in the heterogeneous system world (i.e. SIMATIC systems communicate with “third party” automation systems) this topic is extremely complex. Basic knowledge of the principles behind protocol mechanisms, protocols utilizable with the bus systems, as well as their properties, are just as im- portant as the concrete implementation of a solution approach on the basis of proven application samples. Specific problems with the communication tasks From the user’s or planner’s viewpoint, the following questions may often arise when planning the communication solutions: 1. Which Bus System is available as platform for the planned automation solutions? 2. Which Protocol can be efficiently employed for the planned task on this bus system and will be supported by the systems to be connected? 3. How will these Protocols be used to achieve effectively the desired automation solution? 4. Which further mechanisms are required to solve the given task effi- ciently? Objective of this document The reader is enabled to face the concrete problems within the planning and configuration phase in two steps: 1. The main document which prepares and clearly displays the basic information about possible bus systems and protocols being essential for the user. 2. A collection of the applications, which are complete within themselves, which takes up typical communication problems and offers praxis- oriented solutions by using chosen protocols and further communication mechanisms. The applications are prepared in a way that, on the one hand, the problem- oriented utilization and the embedding of the used protocols in the own user program are shown concretely and, on the other hand, further neces- sary program mechanisms required for solving the problems are explained. Communication with Automation Systems Rev. A - Endgültig 12.04.2004 3/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Addressed group of persons This document and the attached applications as a whole provides both ba- sic knowledge as well as example solutions. This teaching material is cre- ated e.g. for users … • Who want to familiarize themselves with the complex topic “Communication for Automation Systems“ more intensely. • Who need a bus- and protocol oriented overview of all possible constellations within the SIMATIC • Who need a glossary for the topic “Communication with SIMATIC“ User with these demands may be, e.g.: • Starters of the SIMATIC communication • Technically oriented marketing advisors who want to use this teaching material for their presale or planning phase • Project planners / developers, who are looking for testes modules as basis for their own advancement. Structure of this document This document is divided into the 4 following parts: Table 1-1 Part Title with brief description 1 Communication structures in the SIMATIC S7 This chapter gives you an overview of the structural design and the mechanisms of the communication within the SIMATIC. 2 Bus-orientated selection aid of applicable protocols This chapter is intended as selection aid and jump distributor in the protocol summary. 3 Description of the available protocols This chapter comprises a collection of summaries trying to explain in a short and com- parable form the individual protocols. 4 A glossary on term explanation As a conclusion, the terms used in the main document are explained more detailed. Using the hyperlinks This document has been structured by means of hyperlinks to keep the structure of the main document as linear as possible. Each subchapter includes a return jump point to return the next higher level of the hierarchy. The highest level will be reached as soon as chapter 2 Bus-oriented Se- lection Aid of Usable Protocols has been reached. A hyperlink is marked by means of a blue written and underlined text: Back to the bus-oriented selection aid of usable protocols Communication with Automation Systems Rev. A - Endgültig 12.04.2004 4/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Working with this Document There are two ways to use this document • The pragmatic start The user can read the document as of the first chapter and obtain an overview of the available interfaces and the applicable protocols. • The problem-oriented start By means of a concrete problem, a solution for a communication task is sought here. The following steps are performed: Table 1-2 Step Description 1 The start into the document is the “Bus-oriented Selection Aid of Usable Protocols”. Here you can find an overview of the viewed bus systems and their case constellations which can be opened via hyperlinks. 2 On the side opened via the selected hyperlink branch, the available detail constellation is to be carried out or the detail constellation has already been reached. 3 Each detail constellation is represented by an overview of approx. 4 pages. It contains: ○ An overview of the connection case on hand ○ An overview of the possible hardware constellations and the protocol used therein ○ An overview of the properties of the usable protocols as well as ○ An estimate of the performance of the used protocol, if available, as well as an overview of the application samples available for this bus or for the protocol. 4 In the protocol overview, each of the stated protocols can be branched via hyperlinks. This opens a protocol summary outlin- ing the protocol on a further approx. 4 pages. Communication with Automation Systems Rev. A - Endgültig 12.04.2004 5/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Warranty, Liability and Support We do not accept any liability for the information contained in this docu- ment. Any claims against us - based on whatever legal reason - resulting from the use of the examples, information, programs, engineering and perform- ance data etc., described in this document shall be excluded. 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They are only intended to provide support for typical applications. You are responsible in ensuring that the described products are correctly used. These Configurations do not relieve you of the responsibility in safely and professionally using, installing, operating and servicing equipment. When using these Configurations you recognize that Siemens cannot be made li- able for any damage/claims beyond the liability clause described above. We reserve the right to make changes to these Configurations at any time without prior notice. If there are any deviations between the recommenda- tions provided in these Configurations and other Siemens publications - e.g. Catalogs - then the contents of the other documents has priority. Copyright© 2004 Siemens A&D. It is not permissible to transfer or copy these Configurations or excerpts of them without first having prior authorization from Siemens A&D in writing. For questions about this document please use the following e-mail-address: csweb@ad.siemens.de Communication with Automation Systems Rev. A - Endgültig 12.04.2004 6/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Table of Contents 1 Communication Structures in the SIMATIC 8 1.1 Internal communication structures (paths) 8 1.2 External communication structures (paths) 9 1.3 Bus systems 10 1.3.1 Two-point connection 11 1.3.2 Multipoint connection 11 1.3.3 Overview of the bus systems available in SIMATIC 12 1.4 Communication display in the SIMATIC family 13 1.4.1 The S7-200 family 13 1.4.2 The S7-300/400 family 15 1.4.3 WinAC-Basis/RTX 17 1.4.4 WinAC-Slot 18 2 Bus-oriented Selection Aid of Usable Protocols 20 2.1 MPI bus 21 2.1.1 CPU connection external 22 2.1.2 CPU connection internal 26 2.2 PROFIBUS 29 2.2.1 PB CPU – CP connection 30 2.2.2 PB CP-CP connection 36 2.2.3 PB CPU – CPU connection 42 2.2.4 PC Broadcast / Multicast 47 2.3 Industrial Ethernet 51 2.3.1 IE CPU – CP connection 52 2.3.2 IE CP – CP connection 56 2.3.3 IE CPU – CPU connection 61 2.3.4 IE Broadcast / Multicast 64 2.4 Serial Interface 67 2.4.1 PtP- connection 69 2.4.2 PtP Multicast / Broadcast 73 2.5 SIMATIC backplane bus 76 2.5.1 Backplane connection 77 3 Protocol Description 81 3.1 Protocols within SIMATIC S7 82 3.1.1 Global data 84 3.1.2 S7 basic communication (MPI, PB_DP) 88 3.1.3 S7 communication (IE, PB, MPI) 98 3.2 Industrial Ethernet 110 3.2.1 ISO Transport protocol 112 3.2.2 TCP protocol 116 3.2.3 ISO on TCP protocol 120 3.2.4 UDP Protocol 125 3.3 PROFIBUS 130 Communication with Automation Systems Rev. A - Endgültig 12.04.2004 7/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e 3.3.1 FDL protocol 132 3.3.2 DP protocol 140 3.3.3 FMS protocol 148 3.4 Serial Protocols 153 3.4.1 Protocol RK512 155 3.4.2 Procedure 3964(R) 158 3.4.3 Free ASCII protocol 160 3.4.4 Modbus protocol 162 3.4.5 Data highway protocol 172 4 Compendium / Glossary 178 Communication with Automation Systems Rev. A - Endgültig 12.04.2004 8/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e 1 Communication Structures in the SIMATIC Introduction The following chapter deals with the basic principles and concepts of the communication within the SIMATIC environment required for the data ex- change within or between the automation devices. 1.1 Internal communication structures (paths) Introduction The automation system SIMATIC is based on a modular system of modules of different functionalities. To use this system in its modularity, a control mechanism is required via which all parts of the system can communicate with each other. Within the SIMATIC, this task is realized by means of a backplane bus. General display of the backplane bus systems Figure 1-1 The backplane bus system is structured as follows: Communication with Automation Systems Rev. A - Endgültig 12.04.2004 9/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Table 1-1 Bus system Task Communication bus (K-bus) The communication bus (also K-bus) has the task to manage the acyclic data exchange to: • CPs • IP / FMs and • Other CPUs A bus system is available here which also allows for connections between the stations without using the CPU. P-bus (I/O bus) The P-bus (I/O-bus) is responsible for the data exchange between CPU and the centralized I/O. Here, it is possible to access data or to transfer data which are stored in the I/O area of the CPs or IP / FMs. 1.2 External communication structures (paths) Introduction One of the core functionalities in today’s automation world is to coordinate different automation systems with each other. This coordination is made via an up-to-date exchange of data between the individual systems. To connect the systems with each other, communication paths are required enabling even the overcoming of larger distances. These communication paths present themselves in the form of standardized interfaces offering services for data transfer. General presentation of the external communication structure Figure 1-2 The external communication structure can be divided as follows: Communication with Automation Systems Rev. A - Endgültig 12.04.2004 10/185 Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Table 1-2 Interface Description CPU-internal interface CPU-internal interfaces are directly at the CPU. There they are either directly connected to the associated internal bus (e.g. MPI) or directly connected to a proc- essor of the CPU. A direct connection has the advantage that: • Restrictions by the backplane bus will be avoided • thus providing a certain performance advance. External interfaces The external communication interfaces are usually within the station racks or in an expansion rack as a communication module. Some of the communication modules can also be used in the distributed, not intelligent units. A connection of these modules to each other or to a CPU is either made: • Via the communication bus • or the I/O bus. (Decentralized I/O is also as- signed to the I/O) 1.3 Bus systems Introduction The interfaces offered in the SIMATIC family are divided in their physical types of connection into the following groups: • Two-point connections or • Multipoint connections. To provide a simple distinctive possibility the main differences of both types of connection are shown here: Table 1-3 Two-point connection Multipoint connection 1 connection partner for each inter- face n connection partner for each inter- face Small distances bridgeable (approx. 10 – 1000 m) Larger distances bridgeable (much longer than 100 km) Small protocol effort with comparable data transmission security High protocol effort with comparable data transmission security High deterministics High deterministics only via high protocol effort [...]... mistakes and can react purposively (predetermined) By means of a fully programmed example, this application shows an implementation of a functioning routing of data records Via a gateway station, configurable data are sent from one station to the other predefined station which is on another network Client / server communication with (I) Slaves via The Application on hand offers a simple, quick and practical... additional software package ”Industrial Data Bridge” it is also able to use indirectly other communication protocols by means of the OPC server However, out of all the standard functions the WinAC-Basis/RTX is only fixed to the DP and S7 communication Rev A - Endgültig 12.04.2004 17/185 Communication with Automation Systems It is necessary to install the Simatic Net Software for using the communication... offers (CPU 412 or CPU 416) two internal interfaces in both versions: • An MPI / DP interface and • A DP interface Both interfaces can be used as DP master interface The MPI / DP interface can be used either as MPI or DP interface for remote programming, or for connecting to other S7 controllers or for HMI applications, without having to use another CP MPI interfaces (e.g CP 5611) The MPI interface... micro-controllers as well as for the application as data interface for micro-HMI applications PROFIBUS interfaces (e.g CP 5611, CP 5613) The PROFIBUS interface of the WinAC is used as PROFIBUS DP master or as communication interface with other S7 systems via the S7 protocol HMI function is additionally possible There are no other PROFIBUS standard protocols available in the system Rev A - Endgültig 12.04.2004... 20982954_SIMATIC_Comm_DOKU_v10_e The WinAC-Slot is a mixture of a mere HW controller and a Soft-PLC By using the Slot CPU as hardware plug-in card (PCI or ISA format) it works out the PLC program independently from the PC CPU By means of the software package “T-Kit“, an additional software data interface is available enabling a direct data exchange with PC applications Rev A - Endgültig 12.04.2004 19/185 Communication with... be protocol-specific or bus-specific and programming-specific Contents of the selection aid Table 2-1 Bus system Constellation Description Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e CPU connection within a rack without using the backplane bus PB CPU – CP connection PROFIBUS communication between the central processing unit and communication processor PROFIBUS communication... matrix of the hardware constellations • The core information of the available protocols • An overview of the available sample applications for this constellation Advantages of this consideration This consideration enables the purposive selection of the hardware constellation and out of this the selection of the applicable protocol All possible hardware constellations within the SIMATIC S7 family will... constellation is made up as follows: Copyright © Siemens AG 2005 All rights reserved 20982954_SIMATIC_Comm_DOKU_v10_e Bild 2-1 Both stations, station 1 and station 2, consist of one CPU respectively They are built up physically separated from each other And both stations are coupled via the joint MPI bus The data are to be transferred via this connection Rev A - Endgültig 12.04.2004 22/185 Copyright ©... communication examples in the Application Portal and partly on the basis of previous experiences when using protocols Application samples For this constellation, “CPU connection external via MPI”, there are several pre-coded examples which are available in the Application Portal Table 2-5 Application title/ Entry-ID S7 Communication via Profibus CPs with BSEND / BRECEIVE and several Job References (R_IDs) Copyright... connection, when operated under stress i.e continuous data exchange between the stations The application can recognize occurring mistakes and can react purposively (predetermined) This Application describes the synchronization of Client server communication between WinAC Basis and S7.200 station via S7 communication substations via a server station When requested, the server station transfers up to 3 different . mechanisms. The applications are prepared in a way that, on the one hand, the problem- oriented utilization and the embedding of the used protocols in the own user program are shown concretely and, on. problems within the planning and configuration phase in two steps: 1. The main document which prepares and clearly displays the basic information about possible bus systems and protocols being essential. collection of the applications, which are complete within themselves, which takes up typical communication problems and offers praxis- oriented solutions by using chosen protocols and further communication