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Upgrading Security
Published in Frank R. Spellman, The Drinking Water Handbook, 2017
The three major types of electronic controllers are timers, electromechanical relays, and programmable logic controllers (PLCs), which are often called digital relays. Timers use internal signals or inputs (in contrast to externally generated inputs) to generate electronic output signals at certain times. More specifically, timers control electric current flow to any application to which they are connected and can turn the current on or off on a schedule prespecified by the user. Typical timer range (amount of time that can be programmed to elapse before the timer activates linked equipment) is from 0.2 seconds to 10 hours, although some of the more advanced timers have ranges of up to 60 hours. Timers are useful in fixed applications that do not require frequent schedule changes; for example, a timer can be used to turn on the lights in a room or a building at a certain time every day. Timers are usually connected to their own power supply (usually 120 to 240 V).
Data Acquisition Systems
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
The fundamental component of a DAQ system is the plug-in DAQ board. These boards plug directly into a slot in a PC and are available with analog, digital, and timing inputs and outputs (I/O). The most versatile of the plug-in DAQ boards is the multifunction I/O board. As the name implies, this board typically contains various combinations of analog-to-digital converters (ADCs), digital-to-analog converters (DACs), digital I/O lines, and counters/timers. ADCs and DACs measure and generate analog voltage signals, respectively. The digital I/O lines sense and control digital signals. Counters/timers measure pulse rates, widths, delays, and generate timing signals. These many features make the multifunction DAQ board useful for a wide range of applications.
Application
Published in Benny Raphael, Construction and Building Automation, 2023
The energy consumption of electrical lights can be optimized using appropriate control strategies. Visual comfort can also be improved. The common way of controlling the lights is by providing manual switches that can be turned on or off. An improvement to this is using timer-based controls. Timer-based switches are designed to be turned on manually and turned off automatically after a specified time. Both mechanical and electronic timers are available. There are also models that can be programmed to turn on and off at specified times. These are used in places that are briefly occupied such as toilets and plant rooms, where people enter for a short duration. They might forget to turn off the lights when they leave, and energy is wasted.
A creation method of comprehensive cases and specifications for hardware and software combined test to detect undesirable events of an industrial product using HAZOP
Published in SICE Journal of Control, Measurement, and System Integration, 2022
Masakazu Takahashi, Kouji Ueno, Yunarso Anang, Yoshimichi Watanabe
At first, the information that the parameter should have is described. Since the parameters are measurable quantities of the target system, they are the data and control signals handled by the system. Data is input/output through input/output devices such as analog sensors, digital (on/off) sensors, switches (on/off), etc., and control signals are input/output through interrupt control devices and timers. Since the applicable guide words differ depending on the parameter data type, data type such as numeric, character, and boolean value is added to the information. Since the device status changes due to the change of the parameter, information on which device outputs the parameter or which device inputs the parameter is necessary to add. Furthermore, since the parameters are processed by the software part, the information of the corresponding software part is necessary to add. As a result, the parameters have information of one device name, one or more characteristic quantities (data name, data type, output destination (sender), or input source (receiver)), and one or more software parts.
Design and Development of Instrumentation for Remote Detection of Hydrogen Using Metal Oxide Sensor
Published in IETE Technical Review, 2022
Ajay Kumar Keshari, J. Prabhakar Rao, A. Sree Rama Murthy, V. Jayaraman
A microcontroller program was developed using C language for the measurement of resistance of the sensor. The routines in software were written to count the frequency and convert into the concentration of hydrogen. The 8051 microcontroller has two timers, Timer 0 is configured for 400 ms delay as gate period to count the input frequency and Timer 1 is used as a counter to calculate the number of cycles in the gate period of 400 ms. If Timer 1 overflows then the overflow is counted in another register which is considered as the high byte of frequency. The input frequency is connected at P3.5/T1 which is input for Timer 1 in counter mode. LCD is connected to microcontroller port 1 in a 4-bit mode for displaying the data. The count was converted into the resistance of the sensor and sent to LCD and RS-232 for displaying and storing the data in a file.
IoT-enabled cloud-based real-time remote ECG monitoring system
Published in Journal of Medical Engineering & Technology, 2021
Manju Lata Sahu, Mithilesh Atulkar, Mitul Kumar Ahirwal, Afsar Ahamad
Controller: As the core of the ECG module, the controller module is used to process the gathered ECG signal. All the signal processing functions are implemented in a high-performance Microcontroller Unit (MCU) STM32F103RC [31,32]. The STM32F103RC is a high-performance ARM-based 32-bit MCU operating at 72 MHz widely used in applications which require fast digital signal processing. This programmable embedded system on a chip is used with integrated configurable analogue and digital peripherals, memory, timers, CAN and USB communication with UART interface. Apart from this, the system also supports BLE 4.0 and can be connected with other smart systems such as smartphones and personal computer, etc. For this purpose, BMSPPS3MC2 full regulatory certified BLE 4.0 module [33] embedded with 2.4 GHz transceiver, on board Bluetooth stack with the integrated antenna has been used for delivering local connectivity for IoT application. The MCU process the ECG signal in four different steps i.e., sampling, analogue to digital conversion, buffering, and packetizing. Finally, the data are transferred over Bluetooth link through transparent UART interface, which enables easy integration with MCU and bridges the gap between ECG module and mobile gateway for convenient data transfer and control. The ECG signal is processed using this MCU, which consists mainly of four procedures, i.e., sampling, ADC, buffering and packetizing. First, the analogue ECG signal is digitised through sampling and ADC. Then, the ECG data are temporally stored in the buffer before being packaged in accordance with a certain format.