TVB3101-1ISC 1381-644957-16 1308-644957-12 ABB 数字输出

TVB3101-1ISC 1381-644957-16 1308-644957-12  ABB 数字输出

ABB发明、制造了众多产品和技术，其中包括全球第一套三相输电系统、世界上第一台自冷式变压器、高压直流输电技术和第一台电动工业机器人，并率先将它们投入商业应用。ABB拥有广泛的产品线，包括全系列电力变压器和配电变压器，高、中、低压开关柜产品，交流和直流输配电系统，电力自动化系统，各种测量设备和传感器，实时控制和优化系统，机器人软硬件和仿真系统，高效节能的电机和传动系统，电力质量、转换和同步系统，保护电力系统安全的熔断和开关设备。这些产品已广泛应用于工业、商业、电力和公共事业中。

ABB集团位列全球500强企业（2008年在世界500强排列第256位，2009年位列第230位，2010年位列第237位），2009至2011年销售额都高达320亿美元。并在苏黎世、斯德哥尔摩和纽约证券交易所上市交易。

安全回路是保护负载或控制对象以及防止操作错误或控制失败而进行连锁控制的回路。在直接控制负载的同时，安全保护回路还给PLC输入信号，以便于PLC进行保护处理。安全回路一般考虑以下几个方面。

（1）短路保护应该在PLC外部输出回路中装上熔断器，进行短路保护。最好在每个负载的回路中都装上熔断器。

（2）互锁与联锁措施除在程序中保证电路的互锁关系，PLC外部接线中还应该采取硬件的互锁措施，以确保系统安全可靠地运行。

（3）失压保护与紧急停车措施PLC外部负载的供电线路应具有失压保护措施，当临时停电再恢复供电时，不按下“启动”按钮PLC的外部负载就不能自行启动。这种接线方法的另一个作用是，当特殊情况下需要紧急停机时，按下“急停”按钮就可以切断负载电源，同时“急停”信号输入PLC。

（4）极限保护在有些如提升机类超过限位就有可能产生危险的情况下，设置极限保护，当极限保护动作时直接切断负载电源，同时将信号输入PLC。

系统服务器主要负责对域内系统数据的集中管理和监视，包括报警、日志、事故追忆等事件的捕捉和记录管理，并为域内其它各站的数据请求（包括实时数据、事件信息和历史记录）提供服务和为其它域的数据请求提供服务。运行系统以系统服务器为中心，完成所有功能。系统服务器还提供二次数据处理和历史数据管理和存档功能。

现场控制站是DCS系统实现数据采集和过程控制的重要站点，主要完成数据采集、工程单位变换、控制算法处理、输出控制、通过系统网络将数据和诊断结果传送到系统服务器等功能。现场控制站由主控单元、智能I/O单元、电源单元和专用机柜四部分组成，在主控单元和智能I/O单元上，分别固化了实时控制软件和I/O单元运行软件。现场控制站内部采用了分布式的结构，与系统网络相连接的是现场控制站的主控单元，可冗余配置。主控单元通过控制网络（CNET）与各个智能I/O单元实现连接。

TVB3101-1ISC 1381-644957-16 1308-644957-12  ABB 数字输出

ABB invented and manufactured many products and technologies, including the world's first three-phase transmission system, the world's first self-cooled transformer, HVDC transmission technology and the first electric industrial robot, and took the lead in putting them into commercial application. ABB has a wide range of product lines, including a full range of power transformers and distribution transformers, high-,medium-and low-voltage switchgear products, AC and DC power transmission and distribution systems, power automation systems, various measuring equipment and sensors, real-time control and optimization systems, robot software and hardware and simulation systems, high-efficiency and energy-saving motors and transmission systems, power quality, conversion and synchronization systems, and fuse and switch devices to protect the safety of power systems. These products have been widely used in industry, commerce, electricity and public utilities.

ABB Group ranks among the top 500 enterprises in the world (ranked 256th among the top 500 enterprises in 2008, 230th in 2009 and 237th in 2010), and its sales from 2009 to 2011 were as high as $32 billion. It is listed and traded on the stock exchanges of Zurich, Stockholm and new york.

Safety loop is a loop for chain control to protect load or controlled object and prevent operation error or control failure. While directly controlling the load, the safety protection circuit also inputs signals to the PLC, which is convenient for the PLC to carry out protection processing. The safety loop generally considers the following aspects.

(1) short circuit protection should be installed in the PLC external output circuit fuse, short circuit protection. It is best to install a fuse in the loop of each load.

(2) Interlocking and interlocking measures In addition to ensuring the interlocking relationship of the circuit in the program, hardware interlocking measures should also be taken in the external wiring of PLC to ensure the safe and reliable operation of the system.

(3) Pressure loss protection and emergency stop measures The power supply line of PLC external load should have pressure loss protection measures. When power supply is resumed after temporary power failure, the external load of PLC cannot start by itself without pressing the "Start" button. Another function of this wiring method is that when an emergency stop is needed under special circumstances, the load power supply can be cut off by pressing the "emergency stop" button, and the "emergency stop" signal is input to the PLC.

(4) Limit protection In some cases where it is possible to produce danger if the hoist exceeds the limit, limit protection is set, and when the limit protection acts, the load power supply is directly cut off, and the signal is input to PLC.

The system server is mainly responsible for the centralized management and monitoring of system data in the domain, including the capture and record management of alarms, logs, accident memories and other events, and provides services for data requests of other stations in the domain (including real-time data, event information and historical records) and for data requests of other domains. The running system takes the system server as the center and completes all functions. The system server also provides secondary data processing and historical data management and archiving functions.

The field control station is an important station for DCS system to realize data acquisition and process control, which mainly completes the functions of data acquisition, engineering unit transformation, control algorithm processing, output control, and transmitting data and diagnosis results to the system server through the system network. The field control station consists of four parts: main control unit, intelligent I/O unit, power supply unit and special cabinet. On the main control unit and intelligent I/O unit, real-time control software and I/O unit running software are solidified respectively. The field control station adopts a distributed structure, and the main control unit of the field control station is connected with the system network, which can be configured redundantly. The main control unit is connected with each intelligent I/O unit through a control network (CNET).