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IEC 60870 IEC 61850

Our experienced engineering team has extensive knowledge of all relevant IEC standards and many years of experience in their theoretic application in system and data model design as well as their practical application in data model generation, parameterization and programming:
IEC 60870 Communication Standard
The IEC 60870 describes an open communication standard for industrial automation, which is used in the fields of infrastructure automation (control room technology, telecontrol technology, network control technology). The protocol does represent a universal standard, but leaves some leeway for custom-designed applications. The standard for telecontrol technology is based on the following IEC specifications:
IEC 60870-5-1: Transmission Frame Formats
IEC 60870-5-2: Data Link Transmission
IEC 60870-5-3: General Structure of Application Data
IEC 60870-5-4: Definition and Coding of Information Elements
IEC 60870-5-5: Basic Application Functions

With this series of IEC 60870-5 standards, it has been achieved that equipment and systems of station control and telecontrol technology of different manufacturers can communicate with one another without any fundamental adjustment developments. The general description of a protocol standard made it necessary to classify the IEC 60870-5 series of standards into individual parts in order to achieve interoperability of the devices communicating with one another. The following parts of the IEC 60870-5 series of standards have acquired far-reaching significance:

IEC 60870-5-101: Transmission protocols, companion standards especially for basic telecontrol tasks (serial communication)
IEC 60870-5-103: Transmission protocols, companion standard for the informative interface of protection equipment (within a control room)
IEC 60870-5-104: Transmission protocols, network access for IEC 60870-5-101 using standard transport profiles

The interface uses a signal-oriented data model, whereby each telegram represents one data point, such as the message, measurement, counter value, command or alarm. In doing so, this telegram is defined using an address and a data type. The address then determines what the signal is, i.e. the sender and recipient recognize its significance. The series of standards is widely used in communication networks for the monitoring and control of infrastructure networks (electricity, gas, water, pipelines, etc.), particularly in the European and Asian regions.

The following additional specification was created for the networking of technical control facilities:

IEC 60870-6: Remote control protocol (compatible with ISO and ITU standards

The IEC 60870-6 series of standards also includes TASE.2, where services, protocol and an object model are described. With IEC 60870-6 TASE.2, components supplying and using data can be coupled with one another in a standardized manner, whereby this coupling is independent of both the operating system platforms (UNIX, Windows, ...) and the transmitting media (TCP/IP, ISO/OSI, field bus, ...)
IEC 61850  Transmission Protocol
The IEC 61850 describes a general transmission protocolfor protection and network control technology in electrical control rooms of medium and high-voltage technology (station automation). The protocol uses TCP/IP as the basic transmission protocol Manufacturing Messaging Specification (MMS) as a classic client-server communication (see IEC 61850-8-1). In addition, two so-called Peer-to-Peer services for real-time communication are described, which fit directly to the Ethernet protocol (see IEC 61850-8-1 and IEC 61850-9-1).

The data model of the IEC 61850 interface is strictly object-oriented. The name of the object in the clear text acts as the identification. The objects are self-describing, i.e. the structure of the objects is transmitted with the object itself in the telegram. This includes both the communication structures and the strictly object-related data model. However, the standard is designed to be so general that it covers most applications of station automation, but can also supplement industry-specific data models.

In comparison to  IEC 60870-5-104 , IEC 61850 is only defined for the station bus. However, from a technical point of view, the IEC 61850 is also suitable for process data transmission between stations and the superordinate network control technology. Consequently, integrated system architectures are possible without the use of gateways from process, via station control systems to network control stations.

IEC 61850-1: Introduction and overview of the IEC 61850 series standards
IEC 61850-2: Glossary
IEC 61850-3: General requirements, quality requirements, environmental conditions, ancillary services, other standards and codes of practice
IEC 61850-4: System and project management, requirement of engineering services, system usage cycle and quality assurance
IEC 61850-5: Communication requirements for functions and device models, principle of logical nodes, logical communication connections, concept of allocated information elements for communication (PICOM), functions, performance requirements and dynamic scenarios
IEC 61850-6: Configuration language, formal description of the unipolar schema of equipment and system structure as well as its allocation to the unipolar schema
IEC 61850-7: Communication structure, object model and communication principles, description of the abstract interface for communication services and their specification, model of server database, abstract general data classes, definition of logical nodes
IEC 61850-8: Specific communication service mapping, mapping to MMS, mapping of communication within a station, client-server communication and GOOSE telegrams
IEC 61850-8-1: Transmission of  GOOSE messages
IEC 61850-9: Specific communication service mapping, mapping of unidirectional and bus-type communication for samples of converters
IEC 61850-9-1: Transmission of rapid samples
IEC 61850-10: Conformity testing and procedure for conformity testing
IEC 61131 PLC Programming Languages
Based on the international IEC 61131 standard, the European standard EN 61131 deals with the principles of programmable logic controllers (PLC). The standard contains the following parts:

EN 61131-1: Structure and general information
EN 61131-2: Equipment requirements and tests, conformity evaluation
EN 61131-3: Programming languages, guidelines for application and implementation 
EN 61131-5: Communication
EN 61131-7: Fuzzy control programming
IEC TR 611131-4: Application guidelines
IEC TR 61131-8: Programming languages, guidelines for application and implementation

The EN 61131-3 standard is the only valid standard for programming languages of PLCs in the world and defines the following languages:

IL: Instruction list, comparable with Assembler
LL: Ladder logic, comparable with electrical wiring diagram
FBD (FUP): Function block diagram, comparable with logic diagram (for STEP7: FUP)
SC: Sequential control, comparable with phase diagram (for STEP7: GRAPH)
ST: Structured text, comparable with high level programming language (for STEP7: SCL)

In all languages, functions and function blocks can be used, which are written in one of the other languages or provided by PLC manufactures in the form of  Software Libraries without source text. Depending on the performance of the PLC or the programming device, not all languages have to be available. The  conversion between languages is manufacturer-dependent; i.e. not possible or only possible with restricions. Lots of programming environments also offer the option of using other languages, such as  C.

The IL and ST languages are text-based, the other languages (LL, FBD (FUP) and SC) are graphic. In addition, CFC (Continuous Function Chart) is a graphic programming language for PLCs and represents a well-established de-facto standard in the extension of EN 61131-3, although this is not defined there. Its main field of use is 
process control technology because the complex control and regulating tasks occurring there can be mapped very well using CFC.

CFC enables the graphic relay of function blocks as is usual for circuit diagrams in hardware development and can, consequently, be considered as an extension of the function block diagram, in which no strict line-by-line processing from top left to bottom right is needed. Instead, function blocks can be freely positioned and programmers have a multitude of options to link inlets and outlets. The individual function blocks are often written in other PLC languages such as IL or ST and can be supplied by PLC manufacturers as standard components or written by the user independently.

Many process control systems also have process visualization. For this reason, so-called faceplates (prefabricated object and process images) are often already integrated into components with HMI functions (display of statuses and values, operation and control of resources), which can be easily reused on compatible visualization systems.

As a result of the high level of abstraction, translated PLC programs are somewhat more extensive than IL programs, which are closer to hardware. Particularly for complex programs, this can lead to problems with the available PLC internal memory or the PLC cycle time and make it necessary to use a more efficient PLC type.

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