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Introduction into IEC 61131-2

Equipment Requirements and Tests

Scope

  1. This International Standard specifies requirements and related tests for programmable controllers (PLC) and their associated peripherals {e.g., programming and debugging tools (PADTs), human-machine interfaces (HMIs), etc.} which have as their intended use the control and command of machines and industrial processes.
  2. PLCs and their associated peripherals are intended to be used in an industrial environment and may be provided as open or enclosed equipment. If a PLC or its associated peripherals are intended for use in other environments, then the specific requirements, standards and installation practices for those other environments must be additionally applied to the PLC and its associated peripherals.
  3. This standard also applies to any products performing the function of PLCs and/or their associated peripherals.
  4. Equipment covered in this standard is intended for use in overvoltage category II (IEC 60664-1) in low voltage installations, where the rated mains supply voltage does not exceed AC 1000Vr.m.s. (50/60 Hz), or DC 1500V. {If PLCs or their associated peripherals are applied in overvoltage category III installations, then additional analysis will be required to determine the suitability of the equipment for those applications.}
  5. This standard does not deal with the functional safety or other aspects of the overall automated system. PLCs, their application program and their associated peripherals are considered as components of a control system.
  6. Since PLCs are component devices, safety considerations for the overall automated system including installation and application are beyond the scope of this standard. However, PLC safety as related to electric shock and fire hazards, electrical interference immunity and error detecting of the PLC-system operation (such as the use of parity checking, self-testing diagnostics, etc.), are addressed. Refer to IEC 60364 or applicable national/local regulations for electrical installation and guidelines.

Object of the Standard

The purposes of this standard are:
  • To establish the definitions and identify the principal characteristics relevant to the selection and application of PLCs and their associated
    peripherals;
  • To specify the minimum requirements for functional, electrical, mechanical, environmental and construction characteristics, service conditions, safety, EMC, user programming and tests applicable to PLCs and the associated peripherals

Object of This Part

This part specifies:
  1. service, storage and transportation requirements for PLCs and their associated peripherals;
  2. functional requirements for PLCs and their associated;
  3. EMC requirements for PLCs and their associated peripherals;
  4. safety requirements for PLCs and their associated;
  5. information that the manufacturer is required to supply;
  6. test methods and procedures that are to be used for the verification of compliance of PLCs and their associated peripherals with the
    requirements.

The tests are type tests or production routine tests, and not tests related to the ways PLC systems are applied.

Table of Content IEC 61131-2

(incl. page numbers)

1 General 15
1.1 Scope 15
1.2 Object of the Standard 15
1.3 Object of This Part 15
1.4 Compliance With This Standard 16
1.5 Type Tests 16
1.5.1 Equipment to be Tested (Equipment Under Test/EUT) 16
1.5.2 Special Features for Immunity and EMC Tests 18
1.5.3 Withstand Test Conditions 19
1.5.4 Verification Procedure 19
1.5.5 Requirements for Test Programs and Proper Functioning Verification
Procedures (PFVPs) to be Provided by the Manufacturer 		19
1.5.6 General Conditions for Tests 19
1.6 Normative References 20
2 Definitions 21
2.1 Analog Input 21
2.2 Analog Output 21
2.3 Accessible 21
2.4 Basic PLC (-system) 21
2.5 Battery 21
2.6 Clearance 21
2.7 Coating, Protective 21
2.8 Comparative Tracking index (CTI) 22
2.9 Creepage Distance 22
2.10 Current Sinking 22
2.11 Current Sourcing 22
2.12 Digital Input, Type 1 22
2.13 Digital Input, Type 2 22
2.14 Digital Input, Type 3 22
2.15 Digital Output 22
2.16 Earth 22
2.17 EMC (electromagnetic compatibility) 22
2.18 Enclosed Equipment 22
2.19 Enclosure 23
2.20 Equipment class 23
2.21 Equipment Under Test (EUT) 23
2.22 External Wiring 23
2.23 Field wiring 23
2.24 Functional Earthing Conductor 23
2.25 Hand-Held Equipment 23
2.26 Hazardous Live 23
2.27 Immunity (to a disturbance) 23
2.28 Immunity Type Test (immunity test) 23
2.29 Insulation 23
2.29.1 Basic Insulation 24
2.29.2 Double Insulation 24
2.29.3 Reinforced Insulation 24
2.29.4 Supplementary Insulation 24
2.30 Interface 24
2.31 Internal Wiring 24
2.32 Isolated (devices, circuits) 24
2.33 Live Part 24
2.34 Mains Power Supply 24
2.35 Material Group 24
2.36 Micro-Environment: 25
2.37 Module 25
2.38 Multi-Channel Module 25
2.39 Normal Use 25
2.40 Normal Condition 25
2.41 Open Equipment 25
2.42 Operator 25
2.43 Overvoltage Category (of a circuit or within an electrical system) 25
2.44 Permanent Installation 25
2.45 Pollution Degree (in the micro-environment) 25
2.45.1 Pollution Degree 1 26
2.45.2 Pollution Degree 2 26
2.45.3 Pollution Degree 3 26
2.46 Port 26
2.47 Portable Equipment 26
2.48 Protective Conductor 26
2.49 Protective Extra-Low Voltage (PELV) Circuit 26
2.50 Protective Impedance 26
2.51 Recurring Peak Voltage 26
2.52 Routine Test 26
2.53 Safety Extra-Low Voltage Circuit (SELV circuit) 26
2.54 Service Personnel 26
2.55 Total Output Current (of an output module) 27
2.56 Type Test 27
2.57 Unit 27
2.58 Withstand Type Test (withstand test) 27
2.59 Working Voltage 27
3 Normal Service Conditions and Requirements 27
3.1 Climatic Conditions and Requirements 27
3.1.1 Operating Ambient Air Temperature 27
3.1.2 Relative Humidity 28
3.1.3 Altitude 28
3.1.4 Pollution degree 28
3.2 Mechanical Service Conditions and Requirements 28
3.2.1 Vibrations 28
3.2.2 Shocks 28
3.2.3 Free Falls (portable and hand-held equipment) 29
3.3 Transport and Storage Conditions and Requirments 29
3.3.1 Temperature 29
3.3.2 Relative Humidity 29
3.3.3 Altitude 29
3.3.4 Free Falls (PLC units in manufacturer's original packaging) 29
3.3.5 Other Conditions 30
3.4 Electrical Service Conditions and Requirements 30
3.4.1 AC and DC Mains Power Supply 30
3.4.2 Overvoltage Category, Control of Transient Overvoltages 30
3.4.3 Non-Periodic Overvoltages 30
3.5 Special Conditions and Requirements 30
4 Functional Requirements 30
4.1 Functional Power Supply and Memory Back-up Requirements 32
4.1.1 AC and DC Power Supply 32
4.1.1.1 Rated Values and Operating Ranges 32
4.1.1.2 Voltage Harmonics 32
4.1.2 Memory Back-Up 33
4.2 Digital I/Os 33
4.2.1 Digital Inputs (current sinking) 34
4.2.1.1 Terminology (U/I operation regions) 34
4.2.1.2 Standard Operating Ranges for Digital Inputs (current sinking) 35
4.2.1.3 Additional Requirements 35
4.2.2 Digital Outputs for Alternating Currents (current sourcing) 35
4.2.2.1 Rated Values and Operating Ranges (AC) 35
4.2.2.2 Additional Requirements 36
4.2.2.2.1 Output Indicators 36
4.2.2.2.2 Protected Outputs 36
4.2.2.2.3 Short-Circuit Proof Outputs 37
4.2.2.2.4 Non-Protected Outputs 37
4.2.2.2.5 Electromechanical Relay Outputs 37
4.2.3 Digital Outputs for Direct Current (current sourcing) 37
4.2.3.1 Rated Values and Operating Ranges (DC) 37
4.2.3.2 Additional Requirements 38
4.3 Analog I/Os 38
4.3.1 Analog Inputs 38
4.3.2 Analog Outputs 38
4.4 Communication Interface Requirements 39
4.5 Main Processing Unit(s) and Memory(ies) of the PLC-system
Requirements 		39
4.6 Remote Input/Output Stations (RIOSs) Requirements 39
4.7 Peripherals (PADTs, TEs, HMIs) Requirements 39
4.8 PLC-system Self-Tests and Diagnostics Requirements 40
4.9 Functional Earthing 40
4.10 Mounting Requirments 40
4.11 General Marking Requirements 40
4.11.1 Functional Identifications 40
4.11.2 Module Location and Module Identifications 41
4.11.3 Functional Earth Terminals Markings 41
4.12 Requirements for Normal Service and Functional Type Tests and
Verifications 		41
4.13 Requirements for Information on Normal Service and Function 41
5 Normal Service and Functional Type Tests and Verifications 41
5.1 Climatic Tests 41
5.1.1 Dry Heat and Cold Withstand Tests 41
5.1.2 Variation of Temperature 41
5.1.3 Cyclic Damp Heat Withstand Test 42
5.2 Mechanical Tests 42
5.2.1 Vibrations (type test associated with normal service conditions) 42
5.2.2 Shocks (type test associated with normal service conditions) 42
5.2.3 Free Falls (type test associated with normal service conditions) 42
5.2.4 Free Falls (type test associated with transport and storage conditions) 43
5.2.5 Plugging/Unplugging of Removable Units 43
5.3 Verification of Special Functional Requirements for Power Ports and
Memory Back-up -- Special Immunity Limits for Power Ports 		43
5.3.1 Verification of Functional Mains Power Input Port (ac or dc) 43
5.3.1.1 Voltage Range, Voltage Ripple and Frequency Range Test 43
5.3.1.2 Third Harmonic Immunity Test 44
5.3.1.3 Shut-Down Test (sudden supply interruption) 44
5.3.1.4 Start-Up Test 45
5.3.2 External Energy Supply Variation Tests (immunity tests) 45
5.3.2.1 Gradual Shut-Down/Start-Up Test 45
5.3.2.2 Supply Voltage Variation Tests 45
5.3.3 Improper Power Supply Connection Tests 46
5.3.3.1 Reversal of DC Power Supply Polarity Test (withstand test) 46
5.3.3.2 Improper Voltage Level and/or Frequency Test 46
5.3.4 Verification of Memory Back-Up Requirements 46
5.3.4.1 Back-Up Duration Withstand Test 46
5.3.4.2 Verification of Manufacturer's Method of Changing the Energy Source 46
5.3.4.3 Verification of Other Requirements 46
5.4 Verification of Input/Output Requirements 46
5.4.1 General 46
5.4.2 Verification of Digital Inputs 47
5.4.2.1 Operating Range Test 47
5.4.2.2 Reversal of Signal Polarity Test (withstand test) 47
5.4.2.3 Verification of Other Requirements 47
5.4.3 Verification of Digital Outputs 47
5.4.3.1 Operating Range Test 47
5.4.3.2 Test of Protected, Not-Protected, and Short-Circuit Proof Outputs 47
5.4.3.3 Reversal of Signal Polarity Test (withstand test) 47
5.4.3.4 Verification of Other Requirements 48
5.4.4 Verification of Analog I/Os 48
5.4.4.1 Operating Range Tests 48
5.4.4.2 Analog Input Overload Withstand Test 48
5.4.4.3 Short-Circuit Test (voltage output) and Open Circuit Test (current
output) 		48
5.4.4.4 Voltage Supply Variation Test 48
5.4.4.5 Reversal of Signal Polarity Test (withstand test) 48
5.4.4.6 Verification of Other Requirements 48
5.5 Verification of Communication Interface Requirements 49
5.6 Verification of MPU Requirements 49
5.7 Verification of Remote I/O Stations 49
5.7.1 Response Time Test 49
5.7.2 Loss of Communication Test 49
5.7.3 Verification of Other Requirements 49
5.8 Verification of Peripheral (PADTs, TEs, HMIs) Requirements 49
5.9 Verification of PLC-system Self-Tests and Diagnostics 49
5.10 Verification of Markings and Manufacturer's Documentation 49
6 General Information to be Provided by Manufacturer 50
6.1 Information on Type and Content of Documentation 50
6.1.1 Information on Catalogues and Datasheets 50
6.1.2 Information on User's Manuals 50
6.1.3 Information on Technical Documentation 50
6.2 Information on Compliance With This Standard 50
6.3 Information on Reliability 50
6.4 Information on Other Conditions 51
6.5 Information on Shipping and Storage 51
6.6 Information on AC and DC Power Supply 51
6.7 Information on Digital Inputs (current sinking) 51
6.8 Information on Digital Outputs for Alternating Currents (current
sourcing) 		52
6.9 Information on Digital Outputs for Direct Current (current sourcing) 52
6.10 Information on Analog Inputs 52
6.10.1 Information on Analog Inputs Static Characteristics 52
6.10.2 Information on Analog Inputs Dynamic Characteristics 53
6.10.3 Information on Analog Inputs General Characteristics 53
6.10.4 Information on Analog Inputs Miscellaneous Characteristics- 53
6.11 Information on Analog Outputs 53
6.11.1 Information on Analog Outputs Static Characteristics 53
6.11.2 Information on Analog Outputs Dynamic Characteristics 53
6.11.3 Information on Analog Outputs General Characteristics 53
6.11.4 Information on Analog Outputs Miscellaneous Characteristics 54
6.12 Information on Communication Interfaces 54
6.13 Information on Main Processing Unit(s) and Memory(ies) of the PLC-
system 		54
6.14 Information on Remote Input/Output Stations (RIOSs) 55
6.15 Information on Peripherals (PADTs, TEs, HMIs) 55
6.16 Information on Self-Tests and Diagnostics 56
7 Electromagnetic Compatibility (EMC) Requirements 56
7.1 General 56
7.2 Emission Requirements 56
7.2.1 General Requirements for Emission 56
7.2.2 Emission Limits in the Low Frequency Range 56
7.2.3 Emission Limits in the High Frequency Range 56
7.3 EMC Immunity Requirements 57
7.3.1 General 57
7.3.2 Performance Criteria 58
7.3.3 General Radiated Immunity Limits 58
7.3.4 Voltage Drops and Interruptions Power Ports 59
7.4 Requirements for EMC Tests and Verifications 60
7.5 Requirements for Information on EMC 60
8 Electromagnetic Compatibility (EMC) Type Tests and Verifications 60
8.1 Electromagnetic Compatibility Related Tests 60
8.2 Test Environment 60
8.3 Measurement of Radiated Interference 60
8.4 Measurement of Conducted Interference 61
8.5 Electrostatic Discharge 61
8.6 Radio Frequency Electromagnetic Field - Amplitude Modulated 61
8.7 Power Frequency Magnetic Fields 61
8.8 Fast Transient Bursts 62
8.9 High Energy Surges 62
8.10 Conducted Radio Frequency Interference 62
8.11 Damped Oscillatory Wave (for Zone C only) 63
8.12 Voltage Drops and Interruptions Power Ports Type Tests and
Verifications 		63
9 Electromagnetic Compatibility (EMC) Information to be Provided by
Manufacturer 		64
10 Safety Requirements 64
10.1 Protection Against Electrical Shock 64
10.1.1 Permissible limits for accessible parts 64
10.1.1.1 Values in normal condition 64
10.1.1.2 Values in single fault condition 65
10.1.2 Open PLC-system Equipment 65
10.1.3 Enclosed PLC-system Equipment 65
10.1.3.1 Class I Equipment 65
10.1.3.2 Class II Equipment 66
10.1.3.3 Class III Equipment 66
10.1.4 Dielectric Strength 67
10.1.5 Operator accessibility 67
10.1.6 Protection in Normal Condition 67
10.1.7 Protection in Single Fault Condition 68
10.1.7.1 Protective Earthing and Bonding 68
10.1.7.2 Supplemental Insulation 68
10.1.7.3 Protective Impedance 68
10.2 Protection Against the Spread of Fire 68
10.3 Limited Power Circuits 69
10.4 Clearance and Creepage Distances Requirements 69
10.4.1 Clearances Relating to Overvoltage Category II 70
10.4.1.1 Clearances for Other Than Field Wiring Terminals 70
10.4.1.2 Field Wiring Terminal Clearances 71
10.4.2 Clearances for Micro-Environment Where Voltages are Known and
Controlled 		71
10.4.3 Creepage Distances for Basic and Supplementary Insulation 71
10.4.3.1 Minimum Creepage Distances (basic and supplementary insulation) 72
10.4.3.1.1 Minimum Creepage Distances for Other Than Printed Circuit Boards 72
10.4.3.1.2 Minimum Creepage Distances for Printed Circuit Boards 72
10.4.3.2 Creepage Distance Requirements for Recurring Peak Voltages 72
10.4.3.2.1 Rationale 72
10.4.3.2.2 Creepage Distance Requirements for Recurring Peak Voltages 72
10.4.4 Creepage Distances for Double/Reinforced Insulation 72
10.4.5 Creepage for Field Wiring Terminals 72
10.5 Flame Retardant Requirements for Non-Metallic Materials 72
10.5.1 Non-Metallic Enclosure Material 72
10.5.2 Non-Metallic Material Supporting Live Parts 72
10.5.3 Components 72
10.5.3.1 Non-Metallic Components 72
10.5.3.2 Decorative and Labelling Materials 72
10.5.3.3 Internal Wiring or Interconnection Cables 72
10.6 Temperature Limits 72
10.7 Enclosures 72
10.7.1 Open Equipment 72
10.7.2 Enclosed Equipment 72
10.7.2.1 Shafts and Knobs 72
10.7.2.2 Mechanical Strength 72
10.8 Field Wiring Terminals Constructional Requirements 72
10.9 Provisions for Protective Earthing 72
10.9.1 Protective Earthing Constructional Requirements 72
10.9.2 Protective Earthing Terminal 72
10.10 Wiring 72
10.10.1 Internal Wiring 72
10.10.2 Interconnection Wiring 72
10.10.3 Mains Power Input Cord 72
10.11 Switching Devices 72
10.12 Components 72
10.13 Battery Requirements 72
10.14 Maximum Voltage and Minimum Voltage 72
10.15 Markings and Identification 72
10.15.1 External Wiring Terminals Identification 72
10.15.2 Live Parts 72
10.15.3 Protective Earth Terminals Markings 72
10.15.4 Equipment Protected by Double/Reinforced Insulation 72
10.15.5 Equipment Supplied by SELV/PELV 72
10.15.6 Rating Information 72
10.16 Requirements for Safety Type Tests and Verifications 72
10.17 Requirements for Safety Routine Tests and Verifications 72
10.17.1 Requirement for Dielectric Strength Verification 72
10.17.2 Requirement for Protective Earthing Verification 72
10.18 Requirements for Information on Safety 72
11 Safety Type Tests and Verifications 72
11.1 Safety Related Mechanical Tests and Verifications 72
11.1.1 Impact Withstand Test 72
11.1.2 Operator accessibility Tests 72
11.1.3 General Examination of Openings 72
11.1.4 Wire Flexing Test 72
11.1.5 Temperature Test 72
11.1.6 Protective Coating Test 72
11.1.7 Rigidity Test 72
11.1.8 Clearance and Creepage Verification 72
11.1.9 Field Wiring Terminals Constructional Verification 72
11.2 Safety Related Electrical Tests 72
11.2.1 Dielectric Withstand Verification Test 72
11.2.2 Protective Earthing Continuity Test 72
11.2.3 Stored Energy Injury Risk Test 72
11.2.4 Overload Test 72
11.2.5 Endurance Test 72
11.3 Single Fault Condition Test – General 72
11.3.1 Single Fault Condition - Breakdown of Components Test 72
11.3.2 Single Fault Condition - Protective Impedance Test 72
11.3.3 Single Fault Condition - Mains Transformers Test 72
12 Safety Routine Tests 72
12.1 Dielectric Withstand Test 72
12.2 Dielectric Withstand Verification Test 72
12.3 Protective Earthing Test 72
13 Safety Information to be Provided by the Manufacturer