• Title/Summary/Keyword: Timer/Counter

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A New input-filtering method for High Speed Counter module of PLC using embedded timer pulse function of general purpose MPU (범용 MPU 내장 타이머 펄스 출력을 이용한 PLC 고속 카운터 모듈의 입력 필터링 기능 개선)

  • Park, Kang-Hee;Lee, Sang-Beak;Han, Kyoung-Sik
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1798-1799
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    • 2011
  • In this paper, A new cost-effective and accurate input noise rejection method for High Speed Counter module of PLC (Programmable Logic Controller) is proposed. By using combination of simple additional logic circuit and the Timer Pulse function of general purpose MPU, Cost-effectiveness and improvement of accuracy of filtering function can be achieved. This proposed method is verified by simulation. This proposed method is much useful for simple industrial controller based on simple microprocessor because of simplicity, accuracy and low cost.

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Long-Tail Watchdog Timer for High Availability on STM32F4-Based Real-Time Embedded Systems (STM32F4 기반의 실시간 임베디드 시스템의 가동시간 향상을 위한 긴 꼬리 와치독 타이머 기법)

  • Choi, Hayeon;Yun, Jiwan;Park, Seoyeon;Kim, Yesol;Park, Sangsoo
    • Journal of Korea Multimedia Society
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    • v.18 no.6
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    • pp.723-733
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    • 2015
  • High availability is of utmost importance in real-time embedded systems. Temporary failures due to software or hardware faults should not result in a system crash. To achieve high availability, embedded systems typically use a combination of hardware and software techniques. A watchdog timer is a hardware component in embedded microprocessors that can be used to automatically reset the processor if software anomalies are detected. The embedded system relies on a single watchdog timer, however, can be permanently disabled if the timer is not properly configured, e.g. falling into an indefinite loop. STM32F4 provides two different types of watchdog timer in terms of timing accuracy and robustness. In this paper, we propose a hybrid approach, called long-tail watchdog timer, to utilize both timers to achieve self-reliance in embedded systems even though one of timers fails. Experimental results confirm that the proposed approach successfully handles various failure scenarios and present performance comparisons between single watchdog timer and hybrid approach in terms of configuration parameters of watchdog timers in STM32F4, counter value and window size.

Independent PRF Generation and Control for Frequency Phase Calibration on Mono-pulse Radar at a Remote Location (원격지에서 모노펄스 레이더의 주파수 위상 교정을 위한 독립된 펄스반복주파수 생성 및 제어)

  • Yang, Jaewon;Yoo, Seungoh;Yoon, Jaehyuk;Lee, Dongju
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.4
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    • pp.368-373
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    • 2021
  • This paper presents a method of independent pulse repetition frequency(PRF) generation and control for frequency phase calibration on mono-pulse radar at a remote location. In order to generate an independent PRF signal of 320[Hz], pulse width modulation(PWM) of 16-bit timer/counter was applied. For a precision control of PRF signal, 16-bit timer/counter interrupt was changed for each period. Therefore, average frequency of PRF could be controlled by 0.0001[Hz]. To calibrate a frequency phase of mono-pulse radar at a remote location, the proposed PRF generator with a precision control of frequency was used regardless of receiving PRF signal from a radar. For the verification of the proposed PRF generator, theoretical analysis and experimental results are included.

A Study on development of a Programmable Controller (프로그램어블 콘트롤러의 개발)

  • 김용수;김영현
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.20 no.4
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    • pp.16-23
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    • 1983
  • A programmable controller (PC) which can control general sequential process is developed. The Z-8OA microprocessor-based PC includes hardwares such as programming device, input/output modules, timer/counter modules, and power-failure recovery module which for soft-ware, initialization program, monitor program, execution program, and power-failure recovery program are developed. In particular, the PC is designed in such a way that a timer can be used several times in different time intervals and a skip capability is incorporated in the user program to reduce scan time.

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Real-time Processing Method for Windows OS Using MSR_FSB_FREQ Control (MSR_FSB_FREQ 제어를 이용한 윈도우 운영체제에 실시간 처리 방법)

  • Kim, Jong Jin;Lee, Sang Gil;Lee, Cheol Hoon
    • Journal of Korea Multimedia Society
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    • v.24 no.1
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    • pp.95-105
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    • 2021
  • In the case of laptops and tablet PC's that replace desktop, it uses the Windows operating system to provide various functions depending on operating system dependency, the Windows operating system does not support real-time processing because it uses multi-level feedback queue scheduling that extends round-robin scheduling. Also, since the initial value of Local APIC Counter can not be obtained from the Windows 8, the real-time processing function provided through the existing RTiK does not work. In this paper, we calculate Local APIC Counter value by using MSR_FSB_FREQ register to support real-time processing function on tablet PC's. We designed and implemented RTiK+, which provides real-time processing function to guarantee the periodicity by calculating the operation time of accurate timer. In order to verify and evaluate the performance of the implemented the RTiK+, the period was measured by using the Read Time-Stamp Counter(RDTSC) instruction and it was confirmed that it operates normally at 1ms and 0.1ms period.

The Design and Implementation of Open Architecture CNC Software Module by a Real-time Control (실시간 제어에 의한 개방형 CNC 소프트웨어 모듈의 설계 및 구현)

  • 이제필
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.5
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    • pp.54-62
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    • 1999
  • This paper describes the design and implementation of a PC(personal computer) based open architecture machine tool controller. The hardware of open architecture CNC has generally a motion control board on a PC for controlling a servo motor. But this paper describes open architecture hardware that consists of a PC, a counter board a DAC board and a DIO board only. This makes it easy to generate CNC software module in a hardware-independent way. The proposed open architecture CNC software runs on the MS-Windows NT. The paper describes a method of con-trolling servo motors using a real-time timer of MS-Windows NT and a commercial real-time operating system on the MS-Windows. NT. An open and reconfigurable software module is made up of an object and an API(application programming interface). Using the object and the API a new CNC system can be quickly configured to control dif-ferent machine tools. The proposed open architecture CNC system is applied to 4-axis lettering center.

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A Study on Engine Control System Using Micro-Computer (마이크로 컴퓨터를 이용한 차량용 엔진 제어에 관한 기초 연구)

  • 강기문;전병실;황준택
    • Journal of the korean Society of Automotive Engineers
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    • v.7 no.3
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    • pp.64-73
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    • 1985
  • In order to control ignition advance angle, this system is designed with Z-80 CPU, CTC (counter Timer Circuit), PIO(Parallel Input Output), A/D Converter and Memory, etc. Serial pulses from speed sensor and analog voltage from pressure sensor are converted to digital data. In order to reduce the error of ignition advance angle output, the reference of ignition advance angle output is set 56.25 before TDC(Top Dead Center). The table of ignition advance angle and program which have a main routine and subroutines are written into ROM ( 1 K-byte). The experimental result of this system is correspondent to the theoretical values of proposed ignition advance angle table. This system can be utilized to any other type of 4 cylinder vehicles for advance angle control by changing software.

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An Analysis of M/G/1 Vacation Systems with Restriction to the Waiting Time of the First Customer (첫 고객의 대기시간에 제약이 있는 M/G/1 휴가모형의 분석)

  • Hur, Sun;Lee, Jeong Kyoo;Ahn, Suneung
    • Journal of Korean Institute of Industrial Engineers
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    • v.28 no.2
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    • pp.187-192
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    • 2002
  • In this paper we consider an M/G/1 queueing system with vacation. The length of vacation period may be controlled by the waiting time of the first customer. The server goes on vacation as soon as the system is empty, and resumes service either when the waiting time of the leading customer reaches a predetermined value, or when the vacation period is expired, whichever comes first. We consider two types of vacation, say, multiple vacation type and N-policy type. We derive the steady-state distributions of the number of customers at arbitrary time and arbitrary customer's waiting time by means of decomposition property. Also, the mean lengths of busy period, idle period and a cycle time are given.

A Study on the configuration of a Circuit for Thermally Stimulated Current Acqusition (열자격 전류 어퀘지션을 위한 회로 구성에 관한 연구)

  • 이상교;오재한;박희두;박광현;이성일;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.298-301
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    • 1995
  • In this study, the properties of Thermally Stimulated Current is measured automatic Data Acquisition System with a A/D Converter set. The A/D Converter set is configured with DIO 8255(Intel), AMD 9513 Timer/Counter and some Programed Controllers. Especially, the numerical method of asymtotic estimation to separate single relaxation curve and physical factors related to charged particles were obtained rapidely and completely. As a result, the data obtained by automatic Acquisition System need to be corrected to average value and the whole control and inspectation system is needed.

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