UEEIC0018
Diagnose and rectify faults in digital controls systems


Application

This unit involves the skills and knowledge required to diagnose and rectify faults in digital controls systems.

It includes preparing, diagnosing and rectifying faults. It also includes completing and reporting fault diagnosis, interpreting diagrams and technical data, applying knowledge of digital systems to logical fault-finding processes, implementing fault rectification, and safety and functional testing.

No licensing, legislative or certification requirements apply to this unit at the time of publication.


Elements and Performance Criteria

ELEMENTS

PERFORMANCE CRITERIA

Elements describe the essential outcomes.

Performance criteria describe the performance needed to demonstrate achievement of the element.

1

Prepare to diagnose and rectify faults

1.1

Work health and safety (WHS)/occupational health and safety (OHS) requirements and workplace procedures are identified and applied.

1.2

Hazards are identified, risks are assessed and control measures implemented

1.3

Safety hazards not previously identified are reported on job safety assessment and advice on risk control measures is sought from relevant person/s

1.4

Extent of work is determined from reports, other documentation and discussions with appropriate person/s

1.5

Appropriate person/s are consulted to ensure work is coordinated effectively with others

1.6

Tools, equipment and testing devices required for diagnosing faults are obtained in accordance with workplace procedures and checked for correct operation and safety

2

Diagnose and rectify faults

2.1

WHS/OHS risk control measures and procedures for carrying out the work are followed

2.2

Need to test or measure live electrical components is determined in accordance with workplace procedures

2.3

Circuits/machines/plant are checked and isolated in accordance with workplace procedures

2.4

Logical diagnostic methods are applied to diagnose electronic control system apparatus faults by employing measurements and estimations of system operating parameters

2.5

Scenarios are tested as suspected cause of system faults

2.6

Fault causes are identified and relevant person/s engaged where fault is outside scope of digital subsystems

2.7

Faults in electronic components of control system are rectified

2.8

System is tested and verified as operating to specified job requirements

2.9

Unplanned situations are responded to in accordance with workplace procedures in a manner that minimises risk to personnel and equipment

2.10

Methods for dealing with unplanned situations are selected based on safety and specified work outcomes

2.11

Diagnosis and rectification work activities are performed using sustainable energy principles and practices without wasting materials, damaging apparatus, the surrounding environment or services

3

Complete and report fault diagnosis and rectification activities

3.1

WHS/OHS work completion risk control measures and workplace procedures are followed

3.2

Worksite is made safe in accordance with workplace safety procedures

3.3

Rectification of faults is documented in accordance with workplace procedures

3.4

Relevant person/s is notified of system fault rectification in accordance with workplace procedures

Evidence of Performance

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements, performance criteria and range of conditions on at least two separate occasions and include:

applying logical diagnostic methods

applying relevant work health and safety (WHS)/occupational health and safety (OHS) requirements, including implementing risk control measures

applying sustainable energy principles and practices

completing and reporting fault diagnosis and rectification activities

dealing with unplanned events/situations in accordance with workplace procedures in a manner that minimises risk to personnel and equipment

diagnosing and rectifying faults

documenting fault rectification

identifying faults, causes and rectification methods

isolating circuits/machines/plant

obtaining tools, equipment and testing devices

preparing to diagnose and rectify faults

rectifying faults in digital subsystems

testing and measuring live electrical components

using scenarios to test causes of system faults

verifying system operates as intended.


Evidence of Knowledge

Evidence required to demonstrate competence in this unit must be relevant to and satisfy all of the requirements of the elements, performance criteria and range of conditions and include knowledge of:

digital control systems, including:

comparison between analogue and digital signals

advantages of digital control systems

digital/analogue control system

logic gates

truth tables

digital testing devices

numbering systems, including:

the binary number system

the octal number system

the hexadecimal number system

binary addition and subtraction

conversion between numbering systems

binary coded decimal (BCD)

Gray code

the American Standard Code for Information Interchange (ASCII)

combinational logic networks, including:

precautions when handling electronic devices due to electrostatic discharge (ESD)

truth tables

basic operation and characteristics of logic devices

logic probes

verification of operation of logic circuits

logic families and specifications, including:

logic families and specifications

transistor-transistor logic (TTL)

complementary metal oxide silicone (CMOS) logic families

the unit load concept

specifications and features of TTL, TTL low power Schottky (LS) and CMOS logic families

three state and open collector logic

input and output voltage characteristics for CMOS and TTL

comparison of TTL with CMOS logic families

unit load

noise margin

interfacing different logic families

tri-state logic devices

encoders and decoders, including:

weighted and unweighted codes

Gray

BCD

ASCII

half and full adder

error detection

decoder and encoder integrated circuits

multiplexer and demultiplexer integrated circuits

flipflops, including:

RS flipflops

D flipflops

JK flipflops

truth tables and operation

debouncing a switch

timing diagrams

sequential logic

state tables and timing diagrams

registers, including shift registers and data latches

counters, including:

ripple counters using JK flipflops

typical integrated circuit types

characteristics and operation

ripple counters

use of feedback to modify count

circuit verification of a ripple counter

synchronous counters

series and parallel data transfer

multivibrators

interconnecting digital circuits to perform an application

digital-to-analogue (D/A) conversion, including:

industrial applications of D/A converters

summing D/A converters

R-2R D/A converters

verification of circuit operation of an IC D/A converter

analogue-to-digital (A/D) conversion, including:

industrial applications of A/D converters

digital ramp, dual slope, successive approximation and simultaneous (flash) A/D converters

verification of circuit operation of an IC A/D converters

display devices, including:

liquid-crystal display (LCD) devices

light-emitting diode (LED) devices.

operation and characteristics

seven segment LED displays

drive requirements

current limiting

multiplexed displays

seven segment encoding chips

emerging display technologies

digital fault finding, including:

general fault-finding principles

common digital faults

digital test equipment

locating a fault

interfacing logic devices to external loads, including:

interfacing with a transistor

interfacing with a relay

solid state switches

opto-isolator

verification of circuit operation of an opto-coupler

programmable logic devices, including:

programmable logic devices

applications of programmable logic devices

types of programmable logic devices

comparison between different programmable logic devices

programmable array logic (PAL)

programmable logic devices (PLD)

field programmable gate arrays (FPGA)

programming and verifying correct operation of a programmable array logic device

relevant job safety assessments or risk mitigation processes, including risk control measures

relevant manufacturer specifications

relevant WHS/OHS legislated requirements

relevant workplace documentation

relevant workplace policies and procedures

sustainable energy principles and practices

system testing and verification techniques

diagnostic methods including digital fault finding, including:

diagnostic tools, equipment and testing devices

digital control systems, including comparison between analogue and digital signals

numbering systems, including binary number system, octal number system and hexadecimal number system.


Assessment Conditions

Assessors must hold credentials specified within the Standards for Registered Training Organisations current at the time of assessment.

Assessment must satisfy the Principles of Assessment and Rules of Evidence and all regulatory requirements included within the Standards for Registered Training Organisations current at the time of assessment.

Assessment must occur in workplace operational situations where it is appropriate to do so; where this is not appropriate, assessment must occur in simulated workplace operational situations that replicate workplace conditions.

Assessment processes and techniques must be appropriate to the language, literacy and numeracy requirements of the work being performed and the needs of the candidate.

Resources for assessment must include access to:

a range of relevant exercises, case studies and/or other simulations

relevant and appropriate materials, tools, equipment and personal protective equipment (PPE) currently used in industry

applicable documentation, including workplace procedures, equipment specifications, regulations, codes of practice and operation manuals.


Foundation Skills

Foundation skills essential to performance are explicit in the performance criteria of this unit of competency.


Range Statement

Range is restricted to essential operating conditions and any other variables essential to the work environment.

Non-essential conditions may be found in the UEE Electrotechnology Training Package Companion Volume Implementation Guide.

Diagnosing and rectifying faults in digital control systems must include at least four of the following faults:

open circuit

short circuit

incorrect or failed connections

insulation failure

unsafe condition

apparatus/component failure

related mechanical failure


Sectors

Electrotechnology


Competency Field

Instrumentation & Control