人机界面应用程序开发 & PLC编程

人机界面应用程序开发 & PLC编程

Human Machine Interface (HMI) or Operator Interface (OI) is the part of the machine that handles the human machine interaction. The goal of any well 设计ed HMI should be to allow the effective operation and 控制 of the machine from the human end while the machine simultaneously feeds back information that aids the operators decision making process.

At Portland Engineering we specialize in full spectrum HMI/OI 设计 工程 services that are clear, 简洁的, 和响应. We know that information is important and that as humans we can only pay full attention to one thing at a time, 所以我们在不损害美学的前提下尽量减少新鲜感. 因为我们设计和编程人机界面/OI已经很长时间了, 我们还理解某些元素应该是熟悉的和一致的. 我们的设计总是反应迅速，从不迟缓, 它们在整个应用程序中是一致的, 它们的设计考虑到了效率.

一种可编程逻辑控制器制造技术, PLC or programmable 控制ler is a digital computer used for automation of industrial electromechanical processes, 例如工厂装配线上的机械控制. plc被用于许多工业和机器中. plc设计用于多种模拟和数字输入和输出安排, 扩展的温度范围, 抗电噪声性, 耐振动和冲击. Programs to 控制 machine operation are typically stored in battery-backed-up or non-volatile memory. A PLC is an example of a "hard" real-time system since output results must be produced in response to input conditions within a limited time, 否则将导致意想不到的操作.

之前的公司, 控制, 测序, 汽车制造安全联锁逻辑主要由继电器组成, 凸轮计时器, 鼓测序仪, 专用闭环控制器. 因为它们可能有几百个，甚至几千个, the process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire the relays to change their operational characteristics.

数字计算机, 是通用可编程设备, 很快就被应用于工业过程的控制. 早期的计算机需要专业程序员, 严格的温度环境控制, 清洁, 和电能质量. Using a general-purpose computer for 过程控制 required protecting the computer from the plant floor conditions. An industrial 控制 computer would have several attributes: it would tolerate the shop-floor environment, 它将以一种易于扩展的方式支持离散(位形式)输入和输出, 使用它不需要多年的训练, 它将允许其运作受到监控. The response time of any computer system must be fast enough to be useful for 控制; the required speed varying according to the nature of the process. 因为许多工业流程的时间尺度很容易通过毫秒级的响应时间来解决, 现代(快, small, 可靠)电子设备极大地促进了建立可靠的控制器, 特别是因为性能可以用可靠性来权衡.

PLC的功能经过多年的发展，包括顺序继电器控制, 运动控制, 过程控制, 分布式控制系统和网络. 的数据处理, 存储, processing power and communication capabilities of some modern PLCs are approximately equivalent to desktop computers. plc类编程结合远程I/O硬件, 允许通用台式计算机在某些应用中重叠一些plc. Desktop computer 控制lers have not been generally accepted in heavy industry because the desktop computers run on less stable operating systems than do PLCs, and because the desktop computer hardware is typically not 设计ed to the same levels of tolerance to temperature, 湿度, 振动, 以及用于plc的处理器的寿命. 像Windows这样的操作系统并不适合于确定性逻辑执行, with the result that the 控制ler may not always respond to changes of input status with the consistency in timing expected from PLCs. 桌面逻辑应用程序可以在不那么重要的情况下使用, such as laboratory automation and use in small facilities where the application is less demanding and critical, 因为它们通常比plc便宜得多.

The main difference from other computers is that PLCs are armored for severe conditions (such as dust, 水分, 热, 冷)，并有广泛的输入/输出(I/O)安排设施. 这些连接PLC到传感器和驱动器. plc读取限位开关, 模拟过程变量(如温度和压力), 以及复杂定位系统的位置. 在执行器一侧, plc操作电机, 气动或液压缸, 电磁继电器, 螺线管, 或模拟输出. 输入/输出安排可以建立在一个简单的PLC, 或者PLC可能有外部I/O模块连接到计算机网络，插入到PLC.

随着plc变得越来越先进, 开发了改变阶梯执行顺序的方法, 并实现了子程序. This simplified programming could be used to save scan time for high-speed processes; for example, parts of the program used only for setting up the machine could be segregated from those parts required to operate at higher speed.

Special-purpose I/O modules may be used where the scan time of the PLC is too long to allow predictable performance. 精密计时模块, 或计数器模块使用轴编码器, are used where the scan time would be too long to reliably count pulses or detect the sense of rotation of an encoder. 相对较慢的PLC仍然可以解释计算值来控制机器, but the accumulation of pulses is done by a dedicated module that is unaffected by the speed of the program execution.
Modular PLCs have a chassis (also called a rack) into which are placed modules with different functions. 处理器和I/O模块的选择是为特定的应用程序定制的. 一个处理器可以管理多个机架, 可能有成千上万的输入和输出. A special high speed serial I/O link is used so that racks can be distributed away from the processor, 降低大型工厂的布线成本.

PLCs have built in communications ports, usually 9-pin RS-232, but optionally EIA-485 or Ethernet. Modbus、BACnet或DF1通常是通信协议之一. 其他选项包括各种现场总线，如DeviceNet或Profibus. 大多数现代plc可以通过网络与其他系统进行通信, 例如一台运行SCADA系统或web浏览器的计算机, 并可通过人机界面进行交互.

而PLC编程的基本概念是所有制造商共同的, I/O寻址的差异, memory organization and instruction sets mean that PLC programs are never perfectly interchangeable between different makers. 即使是在同一制造商的同一产品线中, 不同的模型可能不能直接兼容.

才能正确理解PLC的操作, 花相当多的时间编程是必要的, 测试, PLC程序调试. PLC系统本身是昂贵的，停机时间通常是非常昂贵的. 除了, 如果PLC编程错误，可能会导致生产力损失和危险的情况. PLC simulation software is a valuable tool in the understanding and learning of PLCs and to keep this knowledge refreshed and up to date.

plc很好地适应了一系列自动化任务. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, 以及系统在其运行周期内的预期变化.

在澳门十大网上博网址，我们是Wonderware的注册系统集成商, 艾伦-布拉德利/罗克韦尔自动化, Matrikon, Ignition and InduSoft; and we work with all major brands of PLC hardware and software. 作为控制系统集成商, there is not a single one of our 200 annual products that does not involve interacting with a PLC in some way. We have more than twenty years of experience providing 设计 工程 and programming services for Programmable Logic Controllers in all types of industries. 如果你需要任何有关PLC的帮助, 把澳门十大网上博网址作为你的资源, 任何时候, 期.

澳门十大网上博网址费率 & 费用