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Firmware for a pressure sensor with HART interfacel
Čožík, Ondřej ; Štohl, Radek (referee) ; Fiedler, Petr (advisor)
The bachelor thesis deals with draft of firmware for a capacitive sensor with HART communication protocol. At first, it briefly describes the HART protocol (principles of communication, frame structure and connectivity devices on the HART bus). Subsequently attention is paid to capacitive sensor description, method of data processing and communication method of the sensor with HART interface. The final part depicts individual parts of the firmware for the capacitive sensor (such as the method of values reading from A/D converter, data reading/writing from/to external or internal EEPROM or calculation of the measured pressure value, its temperature compensation and corresponding current loop, using D/A converter.
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Model of cleaning station for food processing technology controlled by a control system na PROFIBUS network.
Vyskočil, Jaromír ; Sobotka, Milan (referee) ; Pásek, Jan (advisor)
This bachelor’s thesis deals with design, realization and laboratory commissioning of the model of keg / tank cleaning station (CIP) in foodstuff industry. The model uses two cleaning liquids – water and lye. There are several different types of valves used in the CIP model. They serves for inlet and outlet of lye or water and for separation of the both liquids branches. The control system offers monitoring of pressure, volume flow, level of the lye, etc. The measuring devises mostly communicate with PLC via industrial net PROFIBUS-DP and PA. The same net PROFIBUS-DP also provides communication between PLC and distributed control system Festo (valve island). Configuration and set up of the Festo valve island is described in the thesis as well. Further the work presents processing of the analogue values from different transmitters and their representation in a operator panel. Operator panel (OP) serves for control and visualization of the cleaning station. The OP configuration, the screens structure and the full functionality in the CIP station is explained. The individual screen description is incorporated as well. There are three modes of control – manual, semiautomatic and automatic. Automatic control is based on the recipe concept and the cleaning philosophy is split into several phases. The PLC control is presented in the form of flow diagrams algorithms and the program code in STEP7 is enclosed in attachment on CD ROM.
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Universal Tester of Tyco Fire panel
Vítek, Ladislav ; Kalina,, Emil (referee) ; Šteffan, Pavel (advisor)
This work is aimed on design of a device for testing of fire detectors and various components of fire detection system, communicating with the fire panel over a fire bus or a loop. The device generates voltages, supplying the detectors, as well as communicating over the bus generating communication waveforms and performing detection of responses measuring voltage and current on the connection. The loop signal is processed by the developed unit and data or result sent to a PC utilizing USB or RS232 connection. All the parts of the equipment are galvanically isolated to the loop circuit.
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Universal Microcontroller Unit
Kulenda, Vít ; Hynčica, Ondřej (referee) ; Kučera, Pavel (advisor)
Master’s thesis contains description parameters of microcontroller ATMEGA644P, also contains differences between older and newer version of microcontrollers ATMEGA644 and ATMEGA644PA. Inside structure of microcontroller, memories and peripherals are described here. The construction of the universal microcontroller unit is main target of this thesis. The unit contains supply, A/D converter, current loop, communication interfaces, temperature sensor, accelerometer and other. The unit collects and saves data, communicates by interfaces and manages other functions. Using devices and circuits are described in this thesis. Development of software for microcontroller(firmware) are positioned to last part of this thesis. This software control functions of all parts positioned on the unit.
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Loop Powered Field Instrument with HART Interface
Kunz, Jan ; Havránek, Zdeněk (referee) ; Beneš, Petr (advisor)
This diploma thesis describes design and development of creating field instrument demonstration kit. Kit is capable of measuring multiple sensors such as thermocouples, RTDs, or pressure sensors, analogue sensor simulation is also provided. Sensor’s side is isolated from output, which is composed of 4 - 20 mA current loop and HART interface. Current loop also provides power supply and kit can communicate via HART also when alarm current (3,2 mA) is set. Basic safety features like open wire detection, over and undervoltage protection are also implemented.
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Communication & Man-Machine Interface for industrial sensors
Marcoň, Petr ; Fedra, Zbyněk (referee) ; Frýza, Tomáš (advisor)
This thesis describes the possibilities of local and remote sensors configuration. Summary overview of the most common Fieldbus and protocols for remote configuration is performed. The focus is mainly dedicated to the HART protocol that is analyzed from the physical layer to the application layer. Circuit diagram and printed circuit board (PCB) of smart sensor with thermistor probe Pt1000 was designed. The HART protocol allows the smart sensor parameters setting as well. The functionality of remote configuration was tested in HARTWinConf program. The control elements for local sensor configuration, such as buttons, matrix keyboards and touchscreens, are described in the following chapter. Representation of the measurement values on display module is introduced too. The most important parameters and aspect of character LCD, graphics LCD and OLED displays are described in greater details. The DD12864YO-3A OLED display was selected to use with designed temperature smart sensor module. The display shows the loop current, the percentage of current range and the primary value - temperature. As the last step the EMI and EMS tests for all modules were performed.
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Analog 0-20mA to Ethernet convertor
Štreit, Zdeněk ; Štohl, Radek (referee) ; Bradáč, Zdeněk (advisor)
The dissertation deals with a design of an intelligent transmitter of a standard current signal with an Ethernet output port, an implementation of a web interface and Modbus TCP protocol for providing data protection. The introductory part describes standardized analogue technical signals with their possibilities, and characteristics of industrial Ethernet. The subsequent part provides an overview of alternatives to connect analogue signals to Ethernet while using various modules. The thesis continues with a suggestion of an analogue input side of the transmitter in connection with a digital module of Ethernet based on the Rabbit processor in connection with the RCM3200 module. The key part of the dissertation puts forward a proposal of the firmware transmitter and control web interface, shows ways of providing figures measured by the current loop via Ethernet interface for further processing. The final part is devoted to a description of current transmitter ultimate measurement.
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Current loop 0(4) - 20 mA Analyzer
Mládek, Ondřej ; B:TECH,, Petr Dobrovolný, (referee) ; Kahle, Petr (advisor)
The subject of master´s thesis the problematics of current loop. Within the thesis, the basic components of current loop and the possibilities of its usage are described. There has also been an analysis made of the crucial functions of analyzer which is currently being in the process of development. A focus is put on mode of source and measure. The related functions are crucial in terms of testing and simulation of current loop. Furthermore, the SPI is described and it is used to establish access to the analyzer’s display. The usage of FMEA method has been chosen for the purpose of circuit’s reliability assessment. Practical part describes development of the analyzer and its parts. FMEA method application for selected fault states is presented in final part.
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Distributed control systems and its utilization in practise
Otčenášek, Martin ; Škoda, Jan (referee) ; Baxant, Petr (advisor)
In control technique there is evident highly expressive trend of shifting from efficient central managing systems towards smaller systems which are distributed on technology and which are connected by communication bus. There is no need to link all signals to central management system, operation is then distributed and realized directly in individual parts of technology. That’s why these systems are called distributive managing systems. Distributive managing systems are widely used not only in industrial applications but also in buildings, cars, etc..
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