IEC 60870 part 5 Gordon R. Clarke et al, ''Practical modern SCADA protocols: DNP3, 60870.5 and related systems'', Newnes, 2004 is one of the

IEC 60870 In electrical engineering and power system automation, the International Electrotechnical Commission 60870 standards define systems used for telecontrol (supervisory control and data acquisition). Such systems are used for controlling electric pow ...

set of standards which define systems used for telecontrol ( supervisory control and data acquisition) in

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

and power system automation applications. Part 5 provides a communication profile for sending basic telecontrol messages between two systems, which uses permanent directly connected data circuits between the systems. The IEC Technical Committee 57 (Working Group 03) have developed a protocol standard for telecontrol, teleprotection, and associated telecommunications for

electric power Electric power is the rate of transfer of electrical energy within a electric circuit, circuit. Its SI unit is the watt, the general unit of power (physics), power, defined as one joule per second. Standard prefixes apply to watts as with oth ...

systems. The result of this work is IEC 60870-5. Five documents specify the base IEC 60870-5: * IEC 60870-5-1 Transmission Frame Formats * IEC 60870-5-2 Data Link Transmission Services * 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 * IEC 60870-5-6 Guidelines for conformance testing for the IEC 60870-5 companion standards * IEC TS 60870-5-7 Security extensions to IEC 60870-5-101 and IEC 60870-5-104 protocols (applying IEC 62351) The IEC Technical Committee 57 has also generated companion standards: * IEC 60870-5-101 Transmission Protocols - Companion standards especially for basic telecontrol tasks * IEC 60870-5-102 Transmission Protocols - Companion standard for the transmission of integrated totals in electric power systems (this standard is not widely used) * IEC 60870-5-103 Transmission Protocols - Companion standard for the informative interface of protection equipment * IEC 60870-5-104 Transmission Protocols - Network access for IEC 60870-5-101 using standard transport profiles * IEC TS 60870-5-601 Transmission protocols - Conformance test cases for the IEC 60870-5-101 companion standard * IEC TS 60870-5-604 Conformance test cases for the IEC 60870-5-104 companion standard IEC 60870-5-101/102/103/104 are companion standards generated for basic telecontrol tasks, transmission of integrated totals, data exchange from protection equipment and network access of IEC101 respectively.

IEC 60870-5-101

IEC 60870-5-101 EC101is a standard for power system monitoring, control & associated communications for telecontrol, teleprotection, and associated telecommunications for electric power systems. This is completely compatible with IEC 60870-5-1 to IEC 60870-5-5 standards and uses standard asynchronous serial tele-control channel interface between DTE and DCE. The standard is suitable for multiple configurations like point-to-point, star, multidrop etc.

Features

* Supports unbalanced (only master initiated message) & balanced (can be master/slave initiated) modes of data transfer. * Link address and ASDU (Application Service Data Unit) addresses are provided for classifying the end station and different segments under the same. * Data is classified into different information objects and each information object is provided with a specific address. * Facility to classify the data into high priority (class-1) and low priority (class-2) and transfer the same using separate mechanisms. * Possibility of classifying the data into different groups (1-16) to get the data according to the group by issuing specific group interrogation commands from the master & obtaining data under all the groups by issuing a general interrogation. * Cyclic & Spontaneous data updating schemes are provided. * Facility for time synchronization * Schemes for transfer of files-Example:IED's will store disturbance recorder file in the memory, When electrical disturbance is occurred in the field. This file can be retrieved through IEC103 protocol for fault analysis

Frame format

The character format of IEC 101 uses 1 bit each for start, stop and parity, as well as 8 data bits. FT1.2 (defined in IEC 60870-5-1) is used for frame format of IEC 101 which is suitable for

asynchronous serial communication Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Synchronization ( clock recovery) is done by data-embedded signal ...

with

Hamming distance In information theory, the Hamming distance between two String (computer science), strings or vectors of equal length is the number of positions at which the corresponding symbols are different. In other words, it measures the minimum number ...

of 4. This uses 3 types of frame formats - ''Frame with variable length ASDU'', ''Frame with fixed length'' & ''single character''. Single character is used for acknowledgments, fixed length frames are used for commands & variable lengths are used for sending data. The details of variable length frame is given below

Types supported

* Single indication without / with 24 / with 56 bit timestamps. * Double indication without / with 24 / with 56 bit timestamps. * Step position information without / with 24 / with 56 bit timestamps. * Measured value – normalized, scaled, short floating point without / with timestamps. * Bitstring of 32 bit without / with timestamps. * Integrated totals (counters) without / with timestamps. * Packed events (start & tripping ) of protection equipments * Single commands * Double commands * Regulating step command * Set point commands of various data formats * Bitstring commands * Interrogation commands * Clock synchronization & delay acquisition commands * Test & reset commands --

IEC 60870-5-103

IEC 60870-5-103 EC103is a standard for power system control and associated

communication Communication is commonly defined as the transmission of information. Its precise definition is disputed and there are disagreements about whether Intention, unintentional or failed transmissions are included and whether communication not onl ...

s. It defines a companion standard that enables interoperability between protection equipment and devices of a control system in a substation. The device complying with this standard can send the information using two methods for

data transfer Data communication, including data transmission and data reception, is the transfer of data, transmitted and received over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical ...

- either using the explicitly specified application service data units (ASDU) or using generic services for transmission of all the possible information. The standard supports some specific protection functions and provides the vendor a facility to incorporate its own protective functions on private data ranges.

Frame format

IEC 103 uses FT1.2 (defined in IEC 60870-5-1) for frame format having options of ''Frame with variable length'', ''Frame with fixed length'' & ''single character'' similar to IEC 101. Single character is used for acknowledgments, fixed length frames are used for commands & variable lengths are used for sending data. However the frame format of IEC 103 differs from IEC 101 in information object address which is split into function type (ftype) and information number (inumber) in IEC 103. Also IEC 103 can have only single information object in a frame whereas IEC 101 can have multiple information objects. Many of the field sizes are also restricted in IEC 103. The details of variable length frame is given below

Supported types

* Type 1 — Time-tagged message * Type 2 — Time-tagged message with relative time * Type 3 — Measurands I * Type 4 — Time-tagged measurands with relative time * Type 5 — Identification * Type 6 — Time synchronization * Type 7 — Start of General interrogation * Type 8 —- General interrogation termination * Type 9 — Measurands II * Type 10 — Generic data * Type 11 — Generic identification * Type 23–31 — Used for transferring disturbance files

IEC 60870-5-104

IEC 60870-5-104 (IEC 104) protocol is an extension of IEC 101 protocol with the changes in transport, network, link, and physical layer services to suit the complete network access. The standard uses an open

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are ...

interface to network to have connectivity to the LAN (

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, campus, or building, and has its network equipment and interconnects locally managed. LANs facilitate the distribution of da ...

) and routers with different facility (

ISDN Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. ...

X.25 X.25 is an ITU-T standard protocol suite for Packet switched network, packet-switched data communication in wide area network, wide area networks (WAN). It was originally defined by the CCITT, International Telegraph and Telephone Consultative Co ...

Frame Relay Frame Relay (FR) is a standardized wide area network (WAN) technology that specifies the Physical layer, physical and data link layers of digital telecommunications channels using a packet switching methodology. Frame Relay was originally devel ...

etc.) can be used to connect to the

wide area network A wide area network (WAN) is a telecommunications network that extends over a large geographic area. Wide area networks are often established with leased telecommunication circuits. Businesses, as well as schools and government entities, use ...

(WAN). Application layer of IEC 104 is preserved same as that of IEC 101 with some of the data types and facilities not used. There are two separate link layers defined in the standard, which is suitable for data transfer over Ethernet & serial line (PPP -

Point-to-Point Protocol In computer networking, Point-to-Point Protocol (PPP) is a data link layer (layer 2) communication protocol between two routers directly without any host or any other networking in between. It can provide loop detection, authentication, transmissio ...

). The control field data of IEC104 contains various types of mechanisms for effective handling of network data synchronization. The security of IEC 104, by design has been proven to be problematic, as many of the other SCADA protocols developed around the same time. Though the IEC technical committee (TC) 57 have published a security standard IEC 62351, which implements encryption tunneling and network monitoring in an effort to address attacks such as packet replay and man-in-the-middle. Due to the increase in complexity and cost, system owners are reluctant to roll this out on their networks.

References

External links

Eclipse NeoSCADA™
IEC 60870-5-104 client and server Java implementation in Eclipse NeoSCADA™, EPL-licensed
j60870
IEC 60870-5-104 client and server Java library at openmuc.org, GPL-licensed
part5
IEC 60870-5-101 & IEC 60870-5-104 client and server Go implementation, public domain
IEC 60870-5 Training VideosIEC 60870-5-101 - RTU Server and Client Simulator, Windows, Linux Development SDKIEC 60870-5-104 RTU Server and Client Master Simulator, Windows, Linux Development SDKIEC 60870-5-101, IEC 60870-5-103 and IEC 60870-5-104 Slave and Master Simulator for Windows
{{List of IEC standards IEC 60870 Network protocols es:IEC 60870-5-101