8) This describes the required skills and knowledge and their level, required for this unit. Evidence shall show that knowledge has been acquired of safe working practices and diagnosing and rectifying faults in digital control systems. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-EI139A Digital electronic control systems Evidence shall show an understanding of digital electronic control systems to an extent indicated by the following aspects: T1. Digital control systems Comparison between analogue and digital signals Advantages of digital control systems Digital/analog control system Logic gates Truth tables Digital testing devices T2. Numbering systems 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) T3. Combinational Logic Networks 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 T4. 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 T5. Encoders and Decoders weighted and unweighted codes. Gray BCD ASCII Half and full adder Encoders, decoders error detection. decoder and encoder ICs. multiplexer and demultiplexer ICs. T6. Flipflops RS flipflops D flipflops JK flipflops truth tables and operation debouncing a switch timing diagrams Sequential logic State tables and timing diagrams T7. Registers shift registers data latches T8. Counters ripple counters using JK flipflops typical IC 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 T9. Digital to analog conversion 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 T10. Analog to digital conversion 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 T11. Display devices 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 T12. Digital fault finding General fault finding principles Common digital faults Digital test equipment Locating a fault T13. Interfacing logic devices to external loads Interfacing with a transistor Interfacing with a relay Solid state switches Opto-isolator Verification of circuit operation of an opto-coupler. T14. 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 |