SMART / INTELLIGENT TRANSMITTERS AND ACTUATORS

Transcription

1 4 SMART / INTELLIGENT TRANSMITTERS AND ACTUATORS Dr. H. K. Verma Distinguished Professor (EEE) Sharda University, Greater Noida (Formerly: Deputy Director and Professor of Instrumentation Indian Institute of Technology Roorkee) 1

2 CONTENTS 1. Smart / Intelligent Transmitters 2. Smart / Intelligent Actuators 2

3 4.1 Smart / Intelligent Transmitters Smart Transmitter: It is a compact unit comprising a sensor (or sensors), analog signal processing unit, transmitter circuit and a communication port. Intelligent Transmitter: It is a compact unit comprising a sensor (or sensors), analog signal processing unit, data processor, communication interface and a communication port. Variants: A Smart transmitter with analog output B Intelligent transmitter with digital wired input-output C Intelligent transmitter with digital wireless input-output D Intelligent HART transmitter E Intelligent HART transmitter with advanced features 3

4 Smart Transmitter with Analog Output Sensor Analog signal processing Unit (ASPU) Transmitter circuit Analog output port Measurand Analog Output Options: Voltage or current Most common output: 4-20 ma Analog output (represents value of the measurand) 4

5 Intelligent Transmitter with Wired Communication Sensor ASPU ADC Data processing Unit (DPU) interface comm. port Measurand communication (comm.) options: Modbus over RS485 Modbus over TCP/IP Ethernet Foundation Fieldbus CANBus, ProfiBus, etc. input/output ( output represents value of the measurand, input is for configuring the device) 5

6 Intelligent Transmitter with Wireless Communication Antenna RF signal Sensor ASPU ADC Data processing Unit (DPU) interface Measurand communication (comm.) options: Zigbee (most common) Wi-Fi Bluetooth 6

7 Intelligent HART Transmitter Sensor ASPU ADC DPU HART interface HART comm. port Measurand communication (comm.) options: Zigbee (most common) Wi-Fi Bluetooth input/output ( output represents value of the measurand, input is for configuring the device) Analog output (Represents value of the measurand) 7

8 Intelligent HART Transmitter Sensor ASPU ADC Data processing Unit (DPU) interface comm. port Measurand communication (comm.) options: Zigbee (most common) Wi-Fi Bluetooth input/output ( output represents value of the measurand, input is for configuring the device) 8

9 Functions of Microprocessor in Intelligent Transmitters Data Processing Functions 1. Conversion of electrical units to engg. units 2. Noise reduction 3. Linearization of response 4. Auto-calibration Communication Functions 1. Data formatting 2. Error control 3. Timing control 4. Networking 9

10 Intelligent HART Transmitter with Advanced Features Main sensors Compensating sensor ASPU ADC MPU interface port Analog output Input/ output D.C. supply Voltage/current regulator Regulated supply Unregulated supply 10

11 ASPU Details Main sensors Compensating sensor Individual signal conditioning circuits Analog multiplexer Common signal conditioner BLF Conditioned and multiplexed analog signals 11

12 ADC & MPU Section Details RAM ROM Conditioned and multiplexed analog signals ADC P Processed data Timer Watch-dog timer 12

13 Communication Section Details DAC Analog signal (output) Processed data Serial interface port Data (bidirectional) 13

14 Serial Communication Interface Details Transmit data P UART Modem Duplexer Receive data port Data 14

15 4.2 Smart / Intelligent Actuators Smart Actuator: It is a compact unit comprising an actuator and its driver circuit. Intelligent Actuator: It is a compact unit comprising an actuator, its driver circuit, a digital controller, communication interface and a communication port. A feedback sensor may also be included as an optional component. Because of their widespread use in industry, these actuators are mostly linear or angular motion actuators. Variants: A Smart actuator B Intelligent actuator without feedback sensor C Intelligent actuator with feedback sensor 15

16 Smart Actuator Electrical control signal Driver circuit Electromechanical actuator Motion Options: Motion: Linear or angular EM Actuator: Servo-motor or stepper motor Driver circuit: Servo-motor driver or stepper-motor driver 16

17 Intelligent Actuator without Feedback Sensor port interface controller Driver circuit Electromechanical actuator Motion input/output (From/to supervisory control system) feedback from sensor Options: Motion: Linear or angular EM Actuator: Servo-motor or stepper motor Driver circuit: Servo-motor driver or stepper-motor driver controller: Microprocessor or microcontroller Communication: Modbus over RS485, Modbus over TCP/IP, Ethernet, Foundation Fieldbus, CANBus, ProfiBus, etc. 17

18 Intelligent Actuator with Feedback Sensor port input/output (From/to supervisory control system) interface feedback controller Driver circuit Position sensor Options: Motion: Linear or angular EM Actuator: Servo-motor or stepper motor Driver circuit: Servo-motor driver or stepper-motor driver controller: Microprocessor or microcontroller Position sensor: Linear or angular position encoder Communication: Modbus over RS485, Modbus over TCP/IP, Ethernet, Foundation Fieldbus, CANBus, ProfiBus, etc. Electromechanical actuator Motion 18

19 Functions of Microprocessor in Intelligent Actuators Control Functions 1. Comparator (Error detector) 2. Control action generator Communication Functions 1. Data formatting 2. Error control 3. Timing control 4. Networking 19