IEC 60870-5-101:2003

IEC 60870-5-101 ®
Edition 2.1 2015-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
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Telecontrol equipment and systems –
Part 5-101: Transmission protocols – Companion standard for basic telecontrol
tasks
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IEC 60870-5-101 ®
Edition 2.1 2015-11
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Telecontrol equipment and systems –

Part 5-101: Transmission protocols – Companion standard for basic telecontrol

tasks
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.200 ISBN 978-2-8322-3051-0

IEC 60870-5-101 ®
Edition 2.1 2015-11
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Telecontrol equipment and systems –
Part 5-101: Transmission protocols – Companion standard for basic telecontrol
tasks
– 2 – IEC 60870-5-101:2003+AMD1:2015 CSV
© IEC 2015
CONTENTS
FO REW O RD . 7
1 Scope and object . 9
2 Normative references . 9
3 Terms and definitions . 10
4 General rules . 11
4.1 Protocol structure . 11
4.2 Physical layer . 12
4.3 Link layer . 13
4.4 Application laye r . 13
4.5 User process . 13
5 Physical layer . 13
5.1 Selections from ISO and ITU-T standards . 13
5.1.1 ITU-T V.24 or ITU-T V.28 unbalanced interchange circuit . 14
5.1.2 ITU-T X.24 or ITU-T X.27 balanced interchange circuit . 15
5.1.3 Interfaces to switched communication networks . 15
5.1.4 Other compatible interfaces . 15
6 Link layer . 15
6.1 Selections from IEC 60870-5-1: Transmission frame formats . 15
6.2 Selections from IEC 60870-5-2: Link transmission procedures . 16
6.2.1 State transition diagrams . 16
6.2.2 Definitions of time out interval for repeated frame transmission . 25
6.2.3 The use of the different resets . 27
7 Application layer and user process . 28
7.1 Selections from IEC 60870-5-3: General structure of application data . 28
7.2 Selections from IEC 60870-5-4: Definition and coding of application
information elem ents . 30
7.2.1 Type identific ation . 30
7.2.2 Variable structure qualifier . 33
7.2.3 Cause of transmission . 36
7.2.4 COMMON ADDRESS OF ASDUs . 41
7.2.5 INFORMATION OBJECT ADDRESS . 42
7.2.6 Information elements . 44
7.3 Definition and presentation of the specific ASDUs. 58
7.3.1 ASDUs for process information in monitor direction . 59
7.3.2 ASDUs for process information in control direction . 98
7.3.3 ASDUs for system information in monitor direction . 103
7.3.4 ASDUs for system information in control direction . 103
7.3.5 ASDUs for parameter in control dire c tion . 108
7.3.6 ASDUs for file transfer . 112
7.4 Selections from IEC 60870-5-5: Basic application functions . 119
7.4.1 Selections from station initialization . 120
7.4.2 Selections from data acquisition by polling . 120
7.4.3 Selections from cyclic data transmission . 120
7.4.4 Selections from acquisition of events . 120
7.4.5 Selections from station interrogation, outstation interrogation . 120
7.4.6 Selections from clock synchronization . 124

© IEC 2015
7.4.7 Selections from command transmission . 124
7.4.8 Selections from transmission of integrated totals . 124
7.4.9 Selections from parameter loading . 128
7.4.10 Selections from test procedure . 128
7.4.11 Selections from file transfer . 128
7.4.12 Selections from acquisition of transmission delay . 151
7.4.13 Background scan . 151
7.4.14 Read procedure . 151
8 Interoperability . 152
8.1 System or device . 153
8.2 Network configuration . 153
8.3 Physical layer . 153
8.4 Link layer . 154
8.5 Application laye r . 155
8.6 Basic application functions . 160
Annex A (informative) Proof of the synchronization stability of
frame format class FT 1.2 . 164
Annex B (informative) Admittance of line idle intervals between characters of
frame format class FT 1.2 . 180

Figure 1 – Selected standard provisions of the defined telecontrol companion standard . 12
Figure 2 – Interfaces and connections of controlling and controlled stations . 12
Figure 3 – State transition diagram by Grady Booch/Harel. 16
Figure 4 – Unbalanced transmission procedures, primary and secondary stations . 18
Figure 5 – State transition diagram for unbalanced transmission primary to secondary . 19
Figure 6 – State transition diagram for unbalanced transmission secondary to primary . 20
Figure 7 – Balanced transmission procedures, primary and secondary link layers . 22
Figure 8 – State transition diagram for balanced transmission primary to secondary . 23
Figure 9 – State transition diagram for balanced transmission secondary to primary . 24
Figure 10 – Structure of an Application Service Data Unit ASDU . 29
Figure 11 – Type identification . 30
Figure 12 – VARIABLE STRUCTURE QUALIFIER . 33
Figure 13 – Presentation of types of information objects in priority buffers . 35
Figure 14 – CAUSE OF TRANSMISSION field . 36
Figure 15 – Station interrogation via a concentrator station using the originator address . 38
Figure 16 – Command transmission via a concentrator station using the originator
address . 39
Figure 17 – COMMON ADDRESS of ASDUs (one octet) . 41
Figure 18 – COMMON ADDRESS of ASDUs (two octets) . 41
Figure 19 – INFORMATION OBJECT ADDRESS (one octet) . 42
Figure 20 – INFORMATION OBJECT ADDRESS (two octets) . 43
Figure 21 – INFORMATION OBJECT ADDRESS (three octets) . 43
Figure 22 – ASDU: M_SP_NA_1 Single-point information without time tag . 59
Figure 23 – ASDU: M_SP_NA_1 Sequence of single-point information without time tag . 60
Figure 24 – ASDU: M_SP_TA_1 Single-point information with time tag . 61
Figure 25 – ASDU: M_DP_NA_1 Double-point information without time tag . 62

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© IEC 2015
Figure 26 – ASDU: M_DP_NA_1 Sequence of double-point information without time
tag . 62
Figure 27 – ASDU: M_DP_TA_1 Double-point information with time tag . 63
Figure 29 – ASDU: M_ST_NA_1 Sequence of step position information . 64
Figure 30 – ASDU: M_ST_TA_1 Step position information with time tag . 65
Figure 31 – ASDU: M_BO_NA_1 Bitstring of 32 bit . 66
Figure 32 – ASDU: M_BO_NA_1 Sequence of bitstrings of 32 bit . 67
Figure 33 – ASDU: M_BO_TA_1 Bitstring of 32 bit . 68
Figure 36 – ASDU: M_ME_TA_1 Measured value, normalized value with time tag . 70
Figure 37 – ASDU: M_ME_NB_1 Measured value, scaled value . 71
Figure 38 – ASDU: M_ME_NB_1 Sequence of measured values, scaled values . 72
Figure 39 – ASDU: M_ME_TB_1 Measured value, scaled value with time tag . 73
Figure 40 – ASDU: M_ME_NC_1 Measured value, short floating point number . 74
Figure 41 – ASDU: M_ME_NC_1 Sequence of measured values, short floating point
number . 75
Figure 43 – ASDU: M_IT_NA_1 Integrated totals . 77
Figure 46 – ASDU: M_EP_TA_1 Event of protection equipment with time tag . 80
Figure 47 – ASDU: M_EP_TB_1 Packed start events of protection equipment with time
tag . 81
Figure 48 – ASDU: M_EP_TC_1 Packed output circuit information of protection
equipment with time tag . 82
Figure 49 – ASDU: M_PS_NA_1 Packed single-point information with status change
detection . 83
Figure 50 – ASDU: M_PS_NA_1 Sequence of packed single-point information with
status change detection . 84
Figure 52 – ASDU: M_ME_ND_1 Sequence of measured values, normalized values
without quality descriptor . 85
Figure 53 – ASDU: M_SP_TB_1 Single-point information with time tag CP56Time2a . 86
Figure 54 – ASDU: M_DP_TB_1 Double-point information with time tag CP56Time2a . 87
Figure 55 – ASDU: M_ST_TB_1 Step position information with time tag CP56Time2a . 88
Figure 56 – ASDU: M_BO_TB_1 Bitstring of 32 bits with time tag CP56Time2a . 89
Figure 58 – ASDU: M_ME_TE_1 Measured value, scaled value with time tag
CP56Time2a . 91
Figure 59 – ASDU: M_ME_TF_1 Measured value, short floating point number with time
tag CP56Time2a . 93
Figure 60 – ASDU: M_IT_TB_1 Integrated totals with time tag CP56Time2a . 94
Figure 62 – ASDU: M_EP_TE_1 Packed start events of protection equipment with time
tag CP56Time2a . 96
Figure 63 – ASDU: M_EP_TF_1 Packed output circuit information of protection
equipment with time tag CP56Time2a . 97
Figure 64 – ASDU: C_SC_NA_1 Single command . 98
Figure 65 – ASDU: C_DC_NA_1 Double command . 98
Figure 66 – ASDU: C_RC_NA_1 Regulating step com m and . 99
Figure 69 – ASDU: C_SE_NC_1 Set-point command, short floating point number . 101
Figure 70 – ASDU: C_BO_NA_1 Bitstring of 32 bit . 102
Figure 71 – ASDU: M_EI_NA_1 End of initialization . 103
Figure 73 – ASDU: C_CI_NA_1 Counter interrogation command . 104

© IEC 2015
Figure 74 – ASDU: C_RD_NA_1 Read command . 105
Figure 75 – ASDU: C_CS_NA_1 Clock synchronization command. 105
Figure 76 – ASDU: C_TS_NA_1 Test command . 106
Figure 77 – ASDU: C_RP_NA_1 Reset process command . 107
Figure 78 – ASDU: C_CD_NA_1 Delay acquisition command . 107
Figure 79 – ASDU: P_ME_NA_1 Parameter of measured values, normalized value . 108
Figure 80 – ASDU: P_ME_NB_1 Parameter of measured values, scaled value . 109
Figure 81 – ASDU: P_ME_NC_1 Parameter of measured values, short floating point
number . 110
Figure 82 – ASDU: P_AC_NA_1 Parameter activation . 111
Figure 83 – ASDU: F_FR_NA_1 File ready . 112
Figure 84 – ASDU: F_SR_NA_1 Section ready . 113
Figure 85 – ASDU: F_SC_NA_1 Call directory, select file, call file, call section . 114
Figure 86 – ASDU: F_LS_NA_1 Last section, last segment . 115
Figure 87 – ASDU: F_AF_NA_1 ACK file, ACK section . 116
Figure 88 – ASDU: F_SG_NA_1 Segment . 117
Figure 90 – Hierarchical presentation of the allocation of common addresses of ASDUs
to LRUs (example) . 122
Figure 91 – Sequential procedure of station interrogation to all LRUs of a
specific controlled station (example) . 123
Figure 92 – General counter model . 124
Figure 93 – Sequential procedure of spontaneously transmitted integrated totals
(mode A) . 125
Figure 94 – Sequential procedure of interrogation of integrated totals (mode B) . 126
Figure 95 – Sequential procedure of memorizing of integrated totals without reset
(mode C) . 127
Figure 96 – Sequential procedure of memorizing of integrated totals with reset
(mode C) . 127
Figure 97 – Addressing of files (example) . 129
Figure 98 – Request from protection equi pm ent . 131
Figure 99 – Request from substation automation system . 132
Figure 100 – Structure of disturbance data of a protection equipment . 133
Figure 101 – Allocation of data types (ASDUs) of IEC 60870-5-103 to the sections of
disturbance data files . 134
Figure 102 – Allocation of the data unit type 23 to the directory F_DR_TA_1 . 135
Figure 103 – Sequential procedure, transmission of the directory . 138
Figure 104 – Sequential procedure, transmission of disturbance data files . 142
Figure 105 – Record of sequences of events in the section of a data file . 146
Figure 106 – Sequential procedure, transmission of sequences of events. 147
Figure 107 – Section of a data file containing sequences of recorded analogue values . 148
Figure 108 – Sequential procedure, transmission of sequences of recorded analogue
values . 150
Figure 109 – Sequential procedure, read procedure . 151
Figure B.1 – Shift of a character caused by an inverted additional line idle bit . 180
Figure B.2 – Relation of even and odd bit pattern to the parity bit . 180
Figure B.3 – Shifted bit pattern . 181

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© IEC 2015
Table 1 – Selection from ITU-T V.24 or ITU-T V.28 . 14
Table 2 – Selection from ITU-T X.24 or ITU-T X.27 for interfaces to synchronous digital
signal multiplexers . 15
Table 3 – Permissible combinations of unbalanced link layer services . 17
Table 4 – Permissible combinations of balanced link layer services . 21
Table 5 – Time out intervals (T ) depending on frame length, transmission speed and
project specific parameters (examples) . 26
Table 6 – Time out intervals (T ) depending on frame length, transmission speed
and project specific parameters (examples) . 27
Table 7 – Effects of the different resets . 27
Table 8 − Semantics of TYPE IDENTIFICATION – Process information in monitor direction . 31
Table 9 – Semantics of TYPE IDENTIFICATION – Process information in control direction . 32
Table 10 – Semantics of TYPE IDENTIFICATION – System information in monitor direction . 32
Table 11 – Semantics of TYPE IDENTIFICATION – System information in control direction . 32
Table 12 – Semantics of TYPE IDENTIFICATION – Parameter in control direction . 33
Table 13 – Semantics of TYPE IDENTIFICATION – File transfer . 33
Table 14 – Semantics of CAUSE OF TRANSMISSION . 40
Table 15 – ASDUs in the monitor direction which may transmit objects with equal
information object addresses . 44
Table 16 – Respond priorities of the controlled station . 119
Table 17 – ASDUs involved in the station interrogation procedure . 121
Table 18 – Allocation of type identification to type identification (IEC 60870-5-101 and
IEC 60870-5-103) . 136
Table 19 – Example for the definition of information object addresses (directory or
subdirectory) . 136
Table 20 – Allocation of SOF status of file to SOF status of fault (IEC 60870-5-101 and
IEC 60870-5-103) . 137
Table 21 – Type identifications for background scan . 151

© IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSSION
___________
TELECONTROL EQUIPMENT AND SYSTEMS –
Part 5-101: Transmission protocols –
Companion standard for basic telecontrol tasks
FOREWORD
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This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60870-5-101 edition 2.1 contains the second edition (2003-02) [documents 57/605/
FDIS and 57/623/RVD] and its amendment 1 (2015-11) [documents 57/1530/CDV and
57/1592/RVC].
In this Redline version, a vertical line in the margin shows where the technical content is
modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
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© IEC 2015
International Standard IEC 60870-5-101 has been prepared by IEC technical committee 57:
Power system control and associated communications.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of the base publication and its amendment 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,
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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.

© IEC 2015
TELECONTROL EQUIPMENT AND SYSTEMS –

Part 5-101: Transmission protocols –
Companion standard for basic telecontrol tasks

1 Scope and object
This part of IEC 60870-5 applies to telecontrol equipment and systems with coded bit serial
data transmission for monitoring and controlling geographically widespread processes. It
defines a telecontrol companion standard that enables interoperability among compatible
telecontrol equipment. The defined telecontrol companion standard utilizes standards of the
IEC 60870-5 series of documents. The specifications of this standard present a functional
profile for basic telecontrol tasks. Further companion standards, based on the IEC 60870-5
series are under consideration.
This standard defines ASDUs with time tags CP24Time2a which includes three octets binary
time from milliseconds to minutes. In addition to these specifications, ASDUs with time tags
CP56Time2a, which includes seven octets binary time from milliseconds to years, are defined
in this standard (see 6.8 of IEC 60870-5-4 and 7.2.6.18 of this standard).
ASDUs with time tags CP56Time2a are used when the controlling station is not able to add the
time from hours to years unambiguously to the received ASDUs which are tagged from
milliseconds to minutes. This may happen when using networks with uncertain transmission
delays or if temporary failure of a network occurs.
Although this companion standard defines the most important user functions, other than the
actual communication functions, it cannot guarantee complete compatibility and interoperability
between equipment of different vendors. An additional mutual agreement is normally required
between concerned parties regarding the methods of use of the defined communication
functions, taking into account the operation of the entire telecontrol equipment.
Standards specified in this standard are compatible with standards defined in IEC 60870-5-1 to
IEC 60870-5-5 (see Clause 2).
2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
IEC 60050(371):1984, International Electrotechnical Vocabulary (IEV) − Chapter 371:
Telecontrol
IEC 60870-1-1:1988, Telecontrol equipment and systems – Part 1: General considerations −
Section 1: General principles
IEC 60870-5-1:1990, Telecontrol equipment and systems − Part 5: Transmission protocols −
Section 1: Transmission frame formats
IEC 60870-5-2:1992, Telecontrol equipment and systems − Part 5: Transmission protocols −
Section 2: Link transmission procedures

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© IEC 2015
IEC 60870-5-3:1992, Telecontrol equipment and systems – Part 5: Transmission protocols –
Section 3: General structure of application data
IEC 60870-5-4:1993, Telecontrol equipment and systems – Part 5: Transmission protocols –
Section 4: Definition and coding of application information elements
IEC 60870-5-5:1995, Telecontrol equipment and systems – Part 5: Transmission protocols –

Section 5: Basic application functions
IEC 60870-5-103:1997, Telecontrol equipment and systems – Part 5-103: Transmission
protocols – Companion standard for the informative interface of protection equipment
ISO/IEC 8824-1:2000, Information technology – Abstract Syntax Notation One (ASN.1):
Specification of basic notation
ITU-T V.24:2000, List of definitions for interchange circuits between data terminal equipment
(DTE) and data circuit-terminating equipment (DCE)
ITU-T V.28:1993, Electrical characteristics for unbalanced double-current interchange circuits
ITU-T X.24:1988, List of definitions for interchange circuits between Data Terminal Equipment
(DTE) and Data Circuit-terminating Equipment (DCE) on public data networks
ITU-T X.27:1996, Electrical characteristics for balanced double-current interchange circuits
operating at data signalling rates up to 10 Mbit/s
IEEE 754:1985, Binary floating-point arithmetic
3 Terms and definitions
For the purpose of this part of IEC 60870-5, the following definitions apply.
3.1
companion standard
a companion standard adds semantics to the definitions of the basic standard or a functional
profile. This may be expressed by defining particular uses for information objects or by defining
additional information objects, service procedures and parameters of the basic standard
NOTE Companion standards do not alter the standards to which they refer, but make explicit the relationship
between those used together for a specific domain of activity.
3.2
group (of information objects)
selection of COMMON ADDRESSES or INFORMATION ADDRESSES which is specifically defined for a
particular system
3.3
control direction
direction of transmission from the controlling station to a controlled station
3.4
monitor direction
direction of transmission from a controlled station to the controlling station

© IEC 2015
3.5
system parameter
a system parameter (or system-specific parameter) is valid for the complete telecontrol system
which uses this companion standard. The telecontrol system consists of the entire controlled
and controlling stations which may be connected via different network configurations
3.6
network-specific parameter
a network-specific parameter is valid for all the stations which are connected via a particular
network configuration
3.7
station-specific parameter
a station-specific parameter is valid for particular stations
3.8
object-specific parameter
an object-specific parameter is valid for a particular information object or a specific group of
information objects
4 General rules
This Clause provides general rules for constructing companion standards for the transmission
protocol of specific telecontrol systems, using the IEC 60870-5 series protocol.
These general rules are applied in the following Subclauses.
4.1 Protocol structure
The IEC 60870-5 series protocol is based on the three-layer reference model “Enhanced
Performance Architecture” (EPA), as specified in Clause 4 of IEC 60870-5-3.
The physical layer uses ITU-T recommendations that provide binary symmetric and
memoryless transmission on the required medium in order to preserve the high level of data
integrity of the defined block encoding method in the link layer.
The link layer consists of a number of link transmission procedures using explicit LINK
PROTOCOL CONTROL INFORMATION (LPCI) that are capable of carrying APPLICATION SERVICE
DATA UNITs (ASDUs) as link-user data. The link layer uses a selection of frame formats to
provide the required integrity/efficiency and convenience of transmission.
The application user layer contains a number of “Application Functions” that involve the
transmission of APPLICATION SERVICE DATA UNITs (ASDUs) between source and destination.
The application layer of this companion standard does not use explicit APPLICATION PROTOCOL
CONTROL INFORMATION (APCI). This is implicit in the contents of the ASDU DATA UNIT IDENTIFIER
field and in the type of link service used.
Figure 1 shows the Enhanced Performance Architecture model (EPA) and the selected
standard definitions of the companion standard.

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© IEC 2015
Selected application functions
of
User process
IEC 60870-5-5
Selected application information elements
of
IEC 60870-5-4
Application (layer 7)
Selected application service data units
of
IEC 60870-5-3
Selected link transmission procedures
of
IEC 60870-5-2
Link (layer 2)
Selected transmission frame formats
of
IEC 60870-5-1
Selected ITU-T recommendations Physical (layer 1)

IEC  084/03
Figure 1 – Selected standard provisions of the defined
telecontrol companion standard
4.2 Physical layer
The companion standard specifies ITU-T recommendations which define the interfaces
between data circuit terminating equipment (DCE) and data terminating equipment (DTE) of the
controlling and the controlled station (see Figure 2, as well as Figure 2 of IEC 60870-1-1).
Data circuit
Data Terminal Data Circuit Data Circuit Data Terminal
Equipment terminating terminating Equipment
Serial
Equipment Equipment (DTE)
(DTE)
telecontrol
of the of the
(DCE) (DCE)
channel
controlling controlled
station station
IEC  085/03
Figure 2 – Interfaces and connections of controlling and controlled stations
The standard interface between DTE and DCE is the asynchronous ITU-T V.24/ITU-T V.28
interface. The use of the required interface signals depends on the operational mode of the
used transmission channel. Therefore the companion standard defines a selection of
interchange circuits (signals) which may but need not be used.
NOTE Data transmission methods that are used to increase the exploitation of the bandwith of a given
transmission channel should be avoided unless it can be proven that the used method (that usually violates the
required memoryless channel encoding principle) does not reduce the data integrity of the data block encoding
method of the selected frame format in the link layer.

© IEC 2015
4.3 Link layer
IEC 60870-5-2 offers a selection defines a set of link transmission procedures using a control
field and the optional address field. Links between stations may be operated in either an
unbalanced or a balanced transmission mode. Appropriate function codes for the control field
are specified for both modes of operation.
If the links from a central control station (controlling station) to several outstations (controlled
stations) share a common physical channel, then these links must be operated in an
unbalanced mode to avoid the possibility of more than one outstation attempting to transmit on
the channel at the same time. The sequence in which the various outstations are granted
access to transmit on the channel is then determined by an application layer procedure in the
controlling station, see 6.2 in IEC 60870-5-5.
The companion standard specifies whether an unbalanced or a balanced transmission mode is
used, together with which link procedures (and corresponding link function codes) are to be used.
The companion standard specifies an unambiguous address (number) for each link. Each
address may be unique within a specific system, or it may be unique within a group of links
sharing a common channel. The latter needs a smaller address field but requires the
controlling station to map addresses by channel number.
A companion standard shall specify one frame format chosen from those offered in
IEC 60870-5-1. The format chosen shall provide the required data integrity together with
the maximum efficiency available for an acceptable level of convenience of implemen-
tation. In addition, a companion standard specifies the time-out interval (T ) of the primary
station and the maximum permitted reaction time (T ) of the secondary station for all links
r
(see A.1 of IEC 60870-5-2 for details of link timing).
4.4 Application layer
A companion standard shall define appropriate ASDUs from a given general structure in
IEC 60870-5-3. These ASDUs are constructed using the definition and coding specifications for
application information elements given in IEC 60870-5-4.
A companion standard shall specify one chosen order of transport fo
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