菜单
  

    Processing Any Communications Requests
    During the message-processing phase of the scan cycle, the FX2N processes any messages that were received from the communications port or intelligent I/O modules.
    Executing the CPU Self-test Diagnostics
    During this phase of the scan cycle, the FX2N checks for proper operation of the CPU and for the status of any expansion modules.
    Writing to the Digital Outputs
    At the end of every scan cycle, the FX2N writes the values stored in the process-image output register to the digital outputs. (Analog outputs are updated immediately, independently from the scan cycle.)
    Programming Concepts, Conventions, and Features
    The FX2N continuously executes your program to control a task or process. You use GX-Developer to create this program and download it to the FX2N. GX-Developer provides a variety of tools and features for designing, implementing, and debugging your program.
    Guidelines for Designing a Micro PLC System
    There are many methods for designing a Micro PLC system. The following general guidelines can apply to many design projects. Of course, you must follow the directives of your own company’s procedures and the accepted practices of your own training and location.
    Partition Your Process or Machine
    Divide your process or machine into sections that have a level of independence from each other. These partitions determine the boundaries between controllers and influence the functional description specifications and the assignment of resources.
    Create the Functional Specifications Write the descriptions of operation for each section of the process or machine. Include the following topics: I/O points, functional description of the operation, states that must be achieved before allowing action for each actuator (such as solenoids, motors, and drives), description of the operator interface, and any interfaces with other sections of the process or machine.
    Design the Safety Circuits
    Identify equipment requiring hard-wired logic for safety. Control devices can fail in an unsafe manner, producing unexpected startup or change in the operation of machinery. Where unexpected or incorrect operation of the machinery could result in physical injury to people or significant property damage, consideration should be given to the use of electro-mechanical overrides which operate independently of the FX2N to prevent unsafe operations. The following tasks should be included in the design of safety circuits:
    (1)Identify improper or unexpected operation of actuators that could be hazardous.
    (2)Identify the conditions that would assure the operation is not hazardous, and determine how to detect these conditions independently of the FX2N.
    (3)Identify how the CPU and I/O affect the process when power is applied and removed, and when errors are detected. This information should only be used for designing for the normal and expected abnormal operation, and should not be relied on for safety purposes.
    (4)Design manual or electro-mechanical safety overrides that block the hazardous operation
    independent of the CPU.
    (5)Provide appropriate status information from the independent circuits to the FX2N so that
    the program and any operator interfaces have necessary information.
    (6)Identify any other safety-related requirements for safe operation of the process.


    Specify the Operator Stations
    Based on the requirements of the functional specifications, create drawings of the operator stations. Include the following items:
    (1)Overview showing the location of each operator station in relation to the process or machine
    (2)Electrical drawings with the associated I/O of the FX2N CPU or expansion module
    Create the Configuration Drawings
    Based on the requirements of the functional specification, create configuration drawings of the control equipment. Include the following items:
    (1)Overview showing the location of each FX2N in relation to the process or machine
  1. 上一篇:搅拌釜内混合液体的分离涡模拟英文文献和翻译
  2. 下一篇:机械设计英文文献和中文翻译
  1. PLC仿真的虚拟工厂英文文献和中文翻译

  2. PLC可编程控制器的介绍英文文献和中文翻译

  3. 模糊PLC系统的伺服机构英文文献和中文翻译

  4. PLC自动化制造系统英文文献和中文翻译

  5. 动力分析和控制器设计英文文献和中文翻译

  6. PLC工业机器人英文文献和中文翻译

  7. PLC相关问题英文文献和中文翻译

  8. C++最短路径算法研究和程序设计

  9. 江苏省某高中学生体质现状的调查研究

  10. 浅析中国古代宗法制度

  11. 高警觉工作人群的元情绪...

  12. NFC协议物理层的软件实现+文献综述

  13. 巴金《激流三部曲》高觉新的悲剧命运

  14. 上市公司股权结构对经营绩效的影响研究

  15. g-C3N4光催化剂的制备和光催化性能研究

  16. 中国传统元素在游戏角色...

  17. 现代简约美式风格在室内家装中的运用

  

About

优尔论文网手机版...

主页:http://www.youerw.com

关闭返回