IEC TR 61850-10-3:2022

Communication networks and systems for power utility automation - Part 10-3: Functional testing of IEC 61850 systems

IEC TR 61850-10-3:2022(E), which is a technical report, is applicable to testing of applications within substations. It is intended to give practical guidelines to perform the stages of quality assurance defined in IEC 61850-4:2011. However, while the quality assurance in that document begins with the IED manufacturer development stage and focuses on the role of the system integrator this document focuses on end-user requirement fulfilment.
The report may be useful to users applying IEC 61850 to other domains, however testing of IEC 61850 systems outside the substation domain is not within the scope of this document.
This document describes:
• A methodical approach to the verification and validation of a substation solution
• The use of IEC 61850 resources for testing in Edition 2.1
• Recommended testing practices for different use cases
• Definition of the process for testing of IEC 61850 based devices and systems using communications instead of hard wired system interfaces (ex. GOOSE and SV instead of hardwired interfaces)
• Use cases related to protection and control functions verification and testing
This document does not cover the conformance testing of devices according to IEC 61850-10 or methodologies for testing of abstract device independent functions.

General Information

• Status: Published
• Publication Date: 07-Feb-2022
• ICS: 33.200 - Telecontrol. Telemetering
• Technical Committee: TC 57 - Power systems management and associated information exchange
• Current Stage: PPUB - Publication issued
• Start Date: 08-Feb-2022
• Completion Date: 04-Mar-2022

Standards Content (Sample)

IEC TR 61850-10-3 ®
Edition 1.0 2022-02
TECHNICAL
REPORT
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Communication networks and systems for power utility automation –
Part 10-3: Functional testing of IEC 61850 systems
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IEC TR 61850-10-3 ®
Edition 1.0 2022-02
TECHNICAL
REPORT
colour
inside
Communication networks and systems for power utility automation –

Part 10-3: Functional testing of IEC 61850 systems

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.200 ISBN 978-2-8322-1075-7

– 2 – IEC TR 61850-10-3:2022 © IEC 2022
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms, definitions, abbreviated terms and acronyms . 10
3.1 Terms and definitions . 10
3.1.1 Testing types . 10
3.2 Abbreviated terms and acronyms . 13
4 Testing-related features in IEC 61850 . 13
4.1 General . 13
4.2 Test features defined in IEC 61850 . 13
4.2.1 General . 13
4.2.2 Simulation based testing in substations under normal operation . 14
4.2.3 Mode and behavior of functions . 16
4.2.4 Logical devices management hierarchy . 18
4.2.5 Processing of information . 21
4.2.6 Blocking of information . 23
4.2.7 Changing the information source (input reference) for testing . 25
4.2.8 Substitution of information . 26
4.2.9 Use of testing related features . 26
5 Testing of Protection, Automation and Control Devices and Systems . 28
5.1 General . 28
5.2 Test system requirements . 29
6 Test methods, practices and needs . 30
6.1 General . 30
6.2 Testing requirements for IEC 61850 based systems . 30
6.3 The V-Model . 31
6.3.1 General . 31
6.3.2 Unit testing . 31
6.3.3 Integration or subsystem testing . 32
6.3.4 System testing . 32
7 Testing use cases . 32
7.1 General . 32
7.2 Distributed Breaker Failure Protection Scheme . 33
7.2.1 General . 33
7.2.2 Use case description . 33
7.2.3 Breaker Failure Protection Scheme Interfaces . 37
7.3 Distributed Select Before Operate . 38
7.3.1 General . 38
7.3.2 Select Before Operate Scheme Components . 38
7.3.3 Select Before Operate Scheme Interfaces . 41
7.3.4 Select Before Operate Scheme Behavior . 42
7.3.5 Single line diagram . 44
8 Test sequences for the use cases. 46
8.1 Breaker failure protection testing . 46
8.1.1 General . 46

8.1.2 Normal sequence . 46
8.1.3 Fault sequence . 47
8.1.4 Setting the test mode and the simulation state of the line protection
function . 48
8.1.5 Setting the test mode and the simulation state of the breaker failure

function . 49
8.1.6 Setting the test mode and the simulation state of the breaker function . 50
8.1.7 Setting the test mode of the bus bar protection function . 51
8.1.8 Testing the line protection IED . 52
8.1.9 Testing the breaker failure IED A interface . 54
8.1.10 Testing the breaker IED A interface . 56
8.1.11 Testing the breaker failure function End-to-End . 58
8.2 Select Before Operate Scheme Testing. 61
8.2.1 General . 61
8.2.2 Unit testing . 61
8.2.3 Subsystem (Interface) testing . 69
8.2.4 System (End-to-End) testing . 70
9 Modeling requirements related to testing in IEC 61850 . 75
10 Object modeling of test systems . 75
11 Engineering of the test system . 77
12 Impact of the testing system on the substation LAN traffic . 77
13 Functional and cyber security considerations . 78
14 Remote testing . 79
Annex A (informative) Introduction to the used UML notation . 80
A.1 General . 80
A.2 Component diagram . 80
A.3 Sequence diagram . 80
Annex B (informative) Requirements for extensions . 83
B.1 Requirements for extensions in IEC 61850-7-1 . 83
B.2 Requirements for extensions in IEC 61850-7-3 . 83
B.3 Requirements for extensions in IEC 61850-7-4 . 84

Figure 1 – Data used for receiving simulation signals (IEC 61850-7-1 Fig. 40) . 15
Figure 2 – IED with multiple process interfaces . 15
Figure 3 – Processing of test signals (Part 7-1, Figure 42) . 18
Figure 4 – Nesting of logical devices representing the functional hierarchy . 19
Figure 5 – Use of GrRef in the modelling of nested logical devices . 20
Figure 6 – Management hierarchy of nested logical devices . 20
Figure 7 – Processing of the data by a LN depending on the LN behaviour and the
quality attribute of input data . 22
Figure 8 – Data used for logical node inputs/outputs blocking: IEC 61850-7-1:2011,
Figure 39) . 24
Figure 9 – Example of input signals used for testing (IEC 61850-7-1:2011, Figure 41) . 25
Figure 10 – Use of InRef for LN test . 26
Figure 11 – Quality assurance stages of IEC 61850-4:2011 . 28
Figure 12 – Testing stages for site acceptance test as defined in IEC 61850-4:2011 . 29
Figure 13 – V-Model used for system engineering . 31

– 4 – IEC TR 61850-10-3:2022 © IEC 2022
Figure 14 – Single line diagram according to IEC 81346 . 34
Figure 15 – System components (Static) . 36
Figure 16 – System components (Dynamic) . 37
Figure 17 – Select Before Operate Scheme . 39
Figure 18 – Component decomposition of Select Before Operate Scheme . 40
Figure 19 – Allocated interfaces for Select Before Operate Scheme – SLD . 41
Figure 20 – Allocated interfaces for Select Before Operate Scheme. 42
Figure 21 – Simplified SBO scheme behaviour . 44
Figure 22 – Single line diagram . 45
Figure 23 – Normal sequence . 47
Figure 24 – Fault sequence . 48
Figure 25 – Line protection function: Setting the mode and the simulation state . 49
Figure 26 – Breaker failure function: Setting the mode and the simulation state . 50
Figure 27 – Breaker function: Setting the mode and the simulation state. 51
Figure 28 – Bus bar protection function: Setting the mode . 51
Figure 29 – Line protection IED A interface testing . 53
Figure 30 – Interfaces between test system and tested IED for testing of line
protection function . 54
Figure 31 – Breaker failure IED A interface testing . 55
Figure 32 – Interfaces between test system and tested IED for testing of breaker
failure protection function . 56
Figure 33 – Breaker IED A interface testing . 57
Figure 34 – Interfaces between test system and tested IED for testing of breaker
control function . 58
Figure 35 – Breaker failure function end to end testing . 60
Figure 36 – Interfaces between test system and tested IEDs for End-to-End testing of
breaker failure protection scheme . 61
Figure 37 – Unit test of TVTR LN – simplified . 62
Figure 38 – Unit test of TVTR LN . 63
Figure 39 – Unit test of XCBR LN – Scenario 1 – simplified . 64
Figure 40 – Unit test of XCBR LN – Scenario 1 . 66
Figure 41 – Unit test of XCBR LN – Scenario 2 – simplified . 67
Figure 42 – Unit test of XCBR LN – Scenario 2 . 68
Figure 43 – Interface test of CSWI – XCBR LNs . 70
Figure 44 – End-to-end test of SBO scheme . 72
Figure 45 – End-to-end test (positive) . 73
Figure 46 – End to end test (negative #1) . 74
Figure 47 – End to end test (negative #2) . 74
Figure 48 – End to end test (negative #3) . 75
Figure 49 – Simplified object model of test device as an IED Simulator . 76
Figure 50 – Simplified object model of test device as generic Simulator . 76
Figure 51 – Testing of transformer differential protection . 78
Figure 52 – Remote test system . 79
Figure A.1 – Example of a component diagram . 80

Figure A.2 – Sequence diagram example . 81

Table 1 – LD/LN Mode/Beh inheritance . 17
Table 2 – Table A.2 of IEC 61850-7-4:2010/AMD1:2020, Annex A summarizes the
processing principles . 23
Table 3 – Applicable modes for different types of tests . 27
Table A.1 – Description of the component diagram UML elements . 80
Table A.2 – Description of UML elements in a sequence diagram . 82
Table B.1 –Examples of accuracy attributes . 84

– 6 – IEC TR 61850-10-3:2022 © IEC 2022
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
COMMUNICATION NETWORKS AND
SYSTEMS FOR POWER UTILITY AUTOMATION –

Part 10-3: Functional testing of IEC 61850 systems

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC TR 61850-10-3, which is a Technical Report, has been prepared by IEC technical
committee 57: Power systems management and associated information exchange.
The text of this Technical Report is based on the following documents:
Draft Report on voting
57/2199/DTR 57/2328/RVDTR
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Technical Report is English.
A list of all parts in the IEC 61850 series, published under the general title Communication
networks and systems for power utility automation, can be found on the IEC website.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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.

– 8 – IEC TR 61850-10-3:2022 © IEC 2022
INTRODUCTION
The growing success of the IEC 61850 series calls for guidelines for testing of substations
implementing this standard. This Technical Report aims at producing a practical guide for
protection, automation and control (PAC) engineers on best practise for testing of the latest
amended IEC 61850 based devices and systems.
Since the release of the first edition of the IEC 61850 standard in 2002-2005 thousands of
substations have been built making use of the new multi-part standard. Most of those systems
are more integrated and complex than the previously deployed, making use of multi-function
capable IEDs and the rich feature set of IEC 61850. Especially the sending and receiving of
protection trips via GOOSE messaging control commands/indications, monitoring and time
synchronisation information over the same shared equipment or network will need to drive
changes to existing test methods and practices as many of the traditional test boundaries have
changed.
Despite the large number of commissioned IEC 61850 substations, considerable uncertainty
among end-users (system integrators and power utilities) regarding the correct testing
procedures still exists. Devices implemented according to the first edition of the standard also
utilized a limited part of the test related functionality in the standard. Much of the functionality
included in IEC 61850 to allow efficient, functional oriented testing has been clarified and
extended in the second edition of IEC 61850-6, IEC 61850-7-1 to IEC 61850-7-4, IEC 61850-8-
1 and IEC 61850-9-2. Therefore, there is a need to help the industry by describing the methods
and principles for testing the IEC 61850 based applications.
This Technical Report provides insight into the changing requirements and practice of testing
following the introduction of IEC 61850 based devices and systems. One example is the
disappearance of so-called 'hardwired' connections between substation automation devices.
These connections are replaced by communication networks and this means that traditional
simulation and isolation of signals for the purpose of testing is no longer possible.

COMMUNICATION NETWORKS AND
SYSTEMS FOR POWER UTILITY AUTOMATION –

Part 10-3: Functional testing of IEC 61850 systems

1 Scope
This part of IEC 61850, which is a technical report, is applicable to testing of applications within
substations. It is intended to give practical guidelines to perform the stages of quality assurance
defined in IEC 61850-4:2011. However, while the quality assurance in that document begins
with the IED manufacturer development stage and focuses on the role of the system integrator
this document focuses on end-user requirement fulfilment.
The report may be useful to users applying IEC 61850 to other domains, however testing of
IEC 61850 systems outside the substation domain is not within the scope of this document.
This document describes:
• A methodical approach to the verification and validation of a substation solution
• The use of IEC 61850 resources for testing in Edition 2.1
• Recommended testing practices for different use cases
• Definition of the process for testing of IEC 61850 based devices and systems using
communications instead of hard wired system interfaces (ex. GOOSE and SV instead of
hardwired interfaces)
• Use cases related to protection and control functions verification and testing
This document does not cover the conformance testing of devices according to IEC 61850-10
or methodologies for testing of abstract device independent functions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 61850-4:2011, Communication networks and systems for power utility automation - Part 4:
System and project management
IEC 61850-6:2009, Communication networks and systems for power utility automation - Part 6:
Configuration description language for communication in electrical substations related to IEDs
IEC 61850-6:2009/AMD1:2018
IEC 61850-6:2009/AMD1:2018
IEC 61850-7-1:2011, Communication networks and systems for power utility automation - Part
7-1: Basic communication structure - Principles and models
IEC 61850-7-1:2011/AMD1:2020
IEC 61850-7-2:2010, Communication networks and systems for power utility automation - Part
7-2: Basic information and communication structure - Abstract communication service interface
(ACSI)
IEC 61850-7-2:2010/AMD1:2020
– 10 – IEC TR 61850-10-3:2022 © IEC 2022
IEC 61850-7-3:2010, Communication networks and systems for power utility automation - Part
7-3: Basic communication structure - Common data classes
IEC 61850-7-3:2010/AMD1:2020
IEC 61850-7-4:2010, Communication networks and systems for power utility automation - Part
7-4: Basic communication structure - Compatible logical node classes and data object classes
IEC 61850-7-4:2010/AMD1:2020
IEC 61850-8-1:2011, Communication networks and systems for power utility automation - Part
8-1: Specific communication service mapping (SCSM) - Mappings to MMS (ISO 9506-1 and ISO
9506-2) and to ISO/IEC 8802-3
IEC 61850-8-1:2011/AMD1:2020
IEC 61850-9-2:2011, Communication networks and systems for power utility automation - Part
9-2: Specific communication service mapping (SCSM) - Sampled values over ISO/IEC 8802-3
IEC 61850-9-2:2011/AMD1:2020
IEC 61850-10:2012, Communication networks and systems for power utility automation - Part
10: Conformance testing
IEC 81346-2, Industrial systems, installations and equipment and industrial products -
Structuring principles and reference designations - Part 2: Classification of objects and codes
for classes
3 Terms, definitions, abbreviated terms and acronyms
3.1 Terms and definitions
3.1.1 Testing types
3.1.1.1
acceptance tests
tests which serve to verify if an IED or a scheme meets the customer requirements
Note 1 to entry: This could include a specific FAT if it is required by the customer.
3.1.1.2
commissioning tests
test on an item carried out on site, to prove that it is correctly installed and can operate correctly
Note 1 to entry: The commissioning phase is carried out on site (in the substation) when the installation phase is
complete. These tests are performed to ensure the safe and reliable operation of the system with associated
substation interfaces. The commissioning phase is a global operation which follows the installation and runs until the
energization, load tests and adjustments are completed.
[SOURCE: IEC 60050-151:2001, 151-16-24]
3.1.1.3
conformance tests
first of the functional tests of the components of an integrated substation automation system
(SAS)
Note 1 to entry: Every IED or Device Under Test (DUT) which belongs to the SAS, is tested. The conformance tests
are performed to show that the IED are compliant to requirements relative to environment, data model, communication
and functional standards. These tests can be performed by a vendor or by an independent authority who certify test
results.
3.1.1.4
Factory Acceptance Tests (FAT) of schemes and systems
customer agreed functional tests of the specifically manufactured system or its parts, using the
parameter set for the planned application
Note 1 to entry: This test is typically performed in the factory of the system integrator by the use of process
simulating test equipment.
[SOURCE: IEC 61850-4:2011 3.20]
3.1.1.5
installation tests
tests carried out by the contractor after installation in order to verify if the system is ready to be
commissioned
3.1.1.6
interoperability tests
tests applied to an assembly of IEDs of the same or different vendors
Note 1 to entry: They shall demonstrate that these IEDs, when interconnected by a proper communication system,
may operate together, sharing information and performing their functions in a secure way and with specified level of
performance. They should be performed with the customer acceptance during system development and factory
acceptance tests.
3.1.1.7
Communication Interface tests:
tests applied to two function elements of a distributed function interfacing over a substation
communication interface in order to evaluate the impact of the communications architecture and
traffic on the performance of the distributed function or sub function
3.1.1.8
Maintenance Tests
all testing activities which occur after the IED or PAC scheme has been put into service
3.1.1.9
Site Acceptance Tests (SAT)
tests consisting of the verification of each data and control point and the correct functionality
inside the automation system and between the automation system and its operating
environment at the whole installed plant by use of the final parameter set
Note 1 to entry: The SAT is a precondition for the automation system being put into operation.
[SOURCE: IEC 61850-4:2011 3.21]
3.1.1.10
End-to-End test
End-to-end testing is used to ensure that the integrated components of an application function
as expected – from the input from the process to the output to the processTesting Methods
3.1.1.11
black-box testing
testing based upon the requirements with the function or system treated as a "black-box" when
the internal workings of the system are unknown
Note 1 to entry: In black-box testing the system is given a stimulus (input) and if the result (output) is what was
expected, then the test passes. No consideration is given to how the process was completed.
3.1.1.12
bottom-up testing
testing which starts with the function elements and works upwards

– 12 – IEC TR 61850-10-3:2022 © IEC 2022
Note 1 to entry: It involves testing the function elements at the lower levels in the hierarchy, and then working up
the hierarchy of sub-functions until the final function is tested.
3.1.1.13
closed-loop testing
testing characterized by the fact that the output from the device or system under test is looped
back and affects the next stage of the simulation
3.1.1.14
local testing
process where all simulation tasks, the assessment of the tested device performance and the
documentation of the results from the test are performed by the tester at the site of the tested
devices or system using mobile test equipment
3.1.1.15
manual testing
manual testing is the process where most of the simulation tasks, the assessment of the tested
device performance and the documentation of the results from the test are performed manually
by the tester.
3.1.1.16
negative testing
testing process where the system validated against the invalid input data
Note 1 to entry: A negative test checks if a application behaves as expected with its negative inputs.
3.1.1.17
positive testing
testing process where the system is validated against the valid input data
Note 1 to entry: In this testing the tester always checks for only valid set of values and checks if an application
behaves as expected with its expected inputs. The main intention of this testing is to check whether the software
application is not showing an error when not supposed to and showing an error when supposed to.
3.1.1.18
remote testing
process where all simulation tasks, the assessment of the tested device performance and the
documentation of the results from the test are performed by the tester from a remote location
over a communications link to the site of the tested devices or system using test equipment
permanently installed at the site
3.1.1.19
top-down testing
testing method which tests the high levels of a system before testing its detailed functional
components
Note 1 to entry: Testing starts with the overall function test and goes down the hierarchy testing sub-functions until
the function elements at the bottom of the hierarchy are tested.
3.1.1.20
white-box testing
testing based upon the requirements with the internal workings of the function or system known
Note 1 to entry: In white-box testing the system is given a stimulus (input) and if the result (output) is what was
expected, then the test passes, however consideration is also given to how the internal elements of the function
worked.
3.2 Abbreviated terms and acronyms
The following abbreviations and acronyms are used in this document:
BFP: Breaker Failure Protection
GOOSE: Generic Object-Oriented Substation Event
IED: Intelligent Electronic Device
PAC: Protection, Automation and Control
PACS: Protection, Automation and Control System
PUAS: Power Utility Automation System
SAS: Substation Automation System
SBO: Select Before Operate
4 Testing-related features in IEC 61850
4.1 General
Functions in Power Utility Automation Systems (PUAS) are not performed by a single function
element (Logical Node, LN), but implemented through an interaction of multiple Logical Nodes,
each contributing its specific functionality. The different functions may be accommodated in
different logical devices, even hosted by different physical devices, which imposes the usage
of agreed-upon basics:
• standardized function interfaces content and behavior (from a communicational perspective)
through LN,
• evaluation of the information received in a predictable manner,
• exchange of information of a common semantic.
While during normal operation the information flow is defined by the communication
configuration, testing requires a user interference into this scheme prior to the test, to avoid
inadvertent reactions onto information created during testing. Disconnecting of a device under
test is not the appropriate way of doing, moreover as this device may require information from
the other components of the system to perform its function.
The above mentioned basics of IEC 61850 are used for testing purposes to functionally isolate
a definable structure of functions in a system environment without disturbing the components
in normal operation. The following chapters will present the principles of how functional isolation
is achieved.
4.2 Test features defined in IEC 61850
4.2.1 General
Some of the features described in this subclause are not mandatory and therefore may not be
available in all IEDs which conform to IEC 61850. It is in the responsibility of the user to re-
establish operational conditions in the device under test after having finalized the tests.
It shall be well understood which testing-related features defined in IEC 61850 and described
in the following clauses are implemented in the devices used in the substation. The user shall
develop procedures that will use the testing features for virtual isolation of the different active
protection, automation and control devices during the testing in a live substation. This includes
resetting of all interventions made onto controllable elements for testing purposes as well as
clearing of buffers, logs, counters if applicable. Considering the possibility that the actual
operational conditions may include settings which deviate from the as-built status, manipulating
a device under test requires careful considerations. The user is welcome to be supported by
tools during this task.
– 14 – IEC TR 61850-10-3:2022 © IEC 2022
4.2.2 Simulation based testing in substations under normal operation
Simulation in the context of IEC 61850 is the capability of a test device to send messages with
a "simulation" flag activated in parallel to the real message to support the distinction between
the actual messages from the equipment in the live substation and the messages from devices
used for testing purposes. It is NOT related to a generic simulation of the process. It is also the
ability of the subscribing device to process simulated messages.
At the IED level the option to set the logical node LPHD data attribute Sim.stVal to TRUE or
FALSE allows the IED to select the multicast signals that will be processed. In order to test an
IED, Sim.stVal is set to TEST. The test device shall inject GOOSE and/or SV messages with
the simulation flag in the header set to TRUE.
Figure 1 shows IED1 receiving simultaneously two similar GOOSE messages (GOOSE 1). The
GOOSE message from the test simulation device has its message header simulation bit set to
TRUE while the other GOOSE 1 message coming from the configured nominal source has its
simulation bit set to FALSE. The IED1 with its physical device logical node LPHD1 data
Sim.stVal also set to TRUE will listen for messages from the test devices with the Simulation
bit set to TRUE and will process only these GOOSE 1 message after the first such message is
received from the test device. If the data Sim.stVal is set to FALSE it will process the GOOSE 1
message from the actual device that has the simulation bit set to FALSE.
While LPHD1 data Sim.stVal remains TRUE, two other GOOSE messages from actual devices,
GOOSE 2 and GOOSE 3, with simulation bits FALSE will still be processed according to
IEC 61850 as shown in Figure 1 as there are no other GOOSE 2 or GOOSE 3 messages on the
network that have the simulation bit set to TRUE. As soon as there is a GOOSE 2 or GOOSE 3
that has the simulation bit set to TRUE, the device will subscribe to this/these GOOSE.
NOTE 1 Data flow of signals using client/server communication channels to the IED are not affected by the
simulation option bit of LPHD.
NOTE 2 Simulation status is not propagated to the output of the function using simulated streams, i.e. downstream
treatment will not have any means to discriminate between a simulated output and a normal one.
NOTE 3 If LSVS.SimSt is true, subscribed SV messages with the simulation bit set are being received and accepted.
NOTE 4 If LGOS.SimSt is true, subscribed GOOSE messages with the simulation bit set are being received and
accepted.
The simulation is thus not completely equivalent to the use of a "test handle" diverting all input
data associated to a conventional IED since not all input signals systematically come from the
test tool. Also, when designing the test cases and scenarios, the effects of GOOSE coming
from the system under operation shall be taken into account. Depending on the test aim, it might
be preferable to combine the use of LPHD.Sim and the test mode.
___________
In this subclause an IED refers to a LD including a LPHD LN, i.e it will affect also all children LDs in case of
nested LDs to the concerned LD.

Figure 1 – Data used for receiving simulation signals (IEC 61850-7-1 Fig. 40)
Simulation is applicable in the LPHD at the level of the Physical Device
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