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 IEC 60870-5-101 (also known as IEC 101) is an international standard, released at the beginning of the 90ies by  the IEC (International Electrotechnical Commission).

The protocol has found widespread use in the energy sector, and is still used today. It is based on the EPA architecture (Enhanced Performance Architecture) and defines only the physical link and application layers of the OSI model.

Five documents specify the base IEC 60870-5. The documents are:

• 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

The IEC Technical Committee 57 also generated a companion standard IEC 60870-5-101 especially for remote controlled units RTU, connected to a Controlling Station either via V24(RS232) or RS485 serial communication. The IEC 60870-5-101 is based on the five documents IEC 60870-5-1 to 5.

Interoperability between devices by different vendors is ensured by the interoperability list, which is defined by the standard. In the list, the function range is defined for each device by marking the applicable functions. The common denominator between different vendor lists limits the possible function range.

As the original standard left more room for interpretation, there were many different implementations on a wide range of different devices many of which are mutually incompatible. To remedy this situation, major energy utilities, such as RWE, Bayernwerke (E.ON), have developed their own IEC 60870-5-101 based standards. The "Norwegian IEC 870-5-101 User Convention", managing line redundancy in particular, has found wide acceptance in Scandinavian countries.

IEC 60870-5-101 is known for the resilience of its link layer and for its simply structured application layer. The main focus was placed on on performance definition, so that some information needed for data decoding is not transmitted. For data decoding to work, parameter settings such as information object length, ASDU address length etc. need to be correct. This is not much of a problem, as interoperability lists help to achieve this.

Supported Information Types

Process information in monitoring direction :

 

1	Single point information	M_SP_NA_1
2	Single point information with time tag	M_SP_TA_1
3	Double point information	M_DP_NA_1
4	Double point information with time tag	M_DP_TA_1
5	Step position information	M_ST_NA_1
6	Step position information with time tag	M_ST_TA_1
7	Bit string of 32 bit	M_BO_NA_1
8	Bit string of 32 bit with time tag	M_BO_TA_1
9	Measured value, normalized value	M_ME_NA_1
10	Measured value, normalized value with time tag	M_ME_TA_1
11	Measured value, scaled value	M_ME_NB_1
12	Measured value, scaled value with time tag	M_ME_TB_1
13	Measured value, short floating point value	M_ME_NC_1
14	Measured value, short floating point value with time tag	M_ME_TC_1
15	Integrated totals	M_IT_NA_1
16	Integrated totals with time tag	M_IT_TA_1
17	Event or protection equipment with time tag	M_EP_TA_1
18	Packed start events of protection equipment with time tag	M_EP_TB_1
19	Packed output circuit information of protection equipment with time tag	M_EP_TC_1
20	Packed single point information with status change detection	M_PS_NA_1
21	Measured value, normalized value without quality descriptor	M_ME_ND_1

 

Process telegrams with long time tags ( 7 octets ) :

 

30	Single point information with time tag CP56Time2a	M_SP_TB_1
31	Double point information with time tag CP56Time2a	M_DP_TB_1
32	Step position information with time tag CP56Time2a	M_ST_TB_1
33	Bit string of 32 bit with time tag CP56Time2a	M_BO_TB_1
34	Measured value, normalized value with time tag CP56Time2a	M_ME_TD_1
35	Measured value, scaled value with time tag CP56Time2a	M_ME_TE_1
36	Measured value, short floating point value with time tag CP56Time2a	M_ME_TF_1
37	Integrated totals with time tag CP56Time2a	M_IT_TB_1
38	Event or protection equipment with time tag CP56Time2a	M_EP_TD_1
39	Packed start events of protection equipment with time tag CP56time2a	M_EP_TE_1
40	Packed output circuit information of protection equipment with time tag CP56Time2a	M_EP_TF_1

 

Process information in control direction :

 

45	Single command	C_SC_NA_1
46	Double command	C_DC_NA_1
47	Regulating step command	C_RC_NA_1
48	Set point command, normalized value	C_SE_NA_1
49	Set point command, scaled value	C_SE_NB_1
50	Set point command, short floating point value	C_SE_NC_1
51	Bitstring 32 bit	C_BO_NA_1

 

Command telegrams with long time tag ( 7 octets ) :

 

58	( IEC 104 ) Single command with time tag CP56Time2a	C_SC_TA_1
59	( IEC 104 ) Double command with time tag CP56Time2a	C_DC_TA_1
60	( IEC 104 ) Regulating step command with time tag CP56Time2a	C_RC_TA_1
61	( IEC 104 ) Set point command, normalized value with time tag CP56Time2a	C_SE_TA_1
62	( IEC 104 ) Set point command, scaled value with time tag CP56Time2a	C_SE_TB_1
63	( IEC 104 ) Set point command, short floating point value with time tag CP56Time2a	C_SE_TC_1
64	( IEC 104 ) Bitstring 32 bit with time tag CP56Time2a	C_BO_TA_1

 

System informationen in monitoring direction :

 

70

End if initialization

M_EI_NA_1

 

System information in control direction :

 

100	(General-) interrogation command	C_IC_NA_1
101	Counter interrogation command	C_CI_NA_1
102	Read command	C_RD_NA_1
103	Clock synchronization command	C_CS_NA_1
104	Test command	C_TS_NB_1
105	Reset process command	C_RP_NC_1
106	Delay acquisition command	C_CD_NA_1
107	( IEC 104 ) Test command with time tag CP56Time2a	C_TS_TA_1

 

Parameter in control direction :

 

110	Parameter of measured value, normalized value	P_ME_NA_1
111	Parameter of measured value, scaled value	P_ME_NB_1
112	Parameter of measured value, short floating point value	P_ME_NC_1
113	Parameter activation	P_AC_NA_1

 

File transfer :

 

120	File ready	F_FR_NA_1
121	Section ready	F_SR_NA_1
122	Call directory, select file, call file, call section	F_SC_NA_1
123	Last section, last segment	F_LS_NA_1
124	Ack file, ack section	F_AF_NA_1
125	Segment	F_SG_NA_1
126	Directory	F_DR_TA_1
127	( IEC 104 ) QueryLog – Request archive file	F_SC_NB_1

Protocol Features

• Physical Layer

  PCM, Full-duplex operation in balanced mode, half-duplex operation in unbalanced mode

• Link Layer

  Asymmetric transmission (unbalanced mode): Party line or point to point
  Symmetric transmission (balanced mode): Only point to point is possible

• Application Layer

  On-demand transmission (e. g. single indications, analogs, ...)
  Spontaneous transmission (e. g. single indications with time tag, ...)
  Direct command transmission (with select before operate)
  Clock synchronization
  File Transfer

• Address Space

  Common Address of ASDU: 1..65535
  Information object address: 1..16777215
  Link address: 0..65535

•  Readily deployable IEC 101 Server and Client Stack on royalty-free basis
•  Developed in C language and can be ported to any Microcontroller platform
•  Enables faster firmware development of IEC 60870-5-101 enabled field devices
•  Supports all the major ASDU(Monitor, Control, Parameter, File Transfer)

Salient Features

• Written in ANSI-Standard C Source Code, under a strict corporate coding standard, and supports C++, C#
• Can be used with or without a Real Time Operating System (RTOS).
• Transparent licensing scheme - No hidden costs, No deferred payments.
• High performance, robust and scalable architecture
• Provides a simple method for systems Integrators and OEMs to utilize standard tools to implement their systems
• Our stacks are fully compliant with "POSIX" and tested in ubuntu, feroda, Debian, QNX, Linux Embedded OS and Various Cross compiler tool chains.
  Our all protocol stack supports "POSIX compliant operating system"
• Context-based event-driven model
• Multiple Server and Client Simulation
• In a Single Server(link) simulate Multiple Stations (Common Address)
• Supports Background Scan, Cyclic Data Transmission, Double Transmission, Redundancy and File transfer.
• Balanced Mode and Unbalanced Mode Support
• Supports "Select-Before-Operate" and "Direct-Execute" command execution modes
• Our IEC 101 Library supports Cyber-security Features, based on IEC 62351 security standard (Parts 3, 5, and 8)

Nội dung chính

• Supported Information Types
• Protocol Features