UNS0881B-PV2 3BHE050077R0102 是ABB生产的一款可编程控制器，也被称作数字逻辑控制器，它在自动控制领域有着广泛的应用。这款控制器由内部的CPU、指令和数据存储器、输入输出单元、电源模块、数字模拟单元等多个模块组合而成，能够接收（输入）和发送（输出）多种类型的电气或电子信号，并利用这些信号来控制或监控几乎所有类型的机电系统。

UNS0881B-PV2 3BHE050077R0102 可编程控制器的特点包括强大的通用性、易用性、广泛的适用性、高可靠性、强大的抗干扰能力以及简单的编程等。其最大的优势之一是输入/输出功能模块齐全，能够为不同的现场信号（如直流或交流、开关量、数字量或模拟量、电压或电流等）提供相应的模板，并能直接与工业现场设备（如按钮、开关、感应式电流变送器、电动机启动器或控制阀等）连接。它通过总线与CPU主板相连 。

此外，该控制器还具备数字输入模块，这是一种用于连接外部机械触点和电子数字传感器的电子设备，是PLC（可编程逻辑控制器）控制系统的一部分。数字输入模块的主要功能是将现场外部的数字信号转换为PLC内部信号水平，并将其传输到CPU进行程序处理。数字输入模块通常具有输入通道，用于接收外部的开关量或数字信号，例如开关的开合、按钮的按压、传感器信号等。输入电路通常配备有RC滤波电路，以防止因输入触点抖动或外部干扰脉冲引起的错误输入信号 。

UNS0881B-PV2 3BHE050077R0102 is a programmable controller produced by ABB, also known as the digital logic controller, it has a wide range of applications in the field of automatic control. This controller is composed of multiple modules such as internal CPU, instruction and data memory, input and output unit, power module, digital analog unit, etc., which can receive (input) and send (output) various types of electrical or electronic signals, and use these signals to control or monitor almost all types of electromechanical systems.

UNS0881B-PV2 3BHE050077R0102 Programmable controller features include strong versatility, ease of use, wide applicability, high reliability, strong anti-interference ability and simple programming. One of its biggest advantages is that the input/output function module is complete, can provide the corresponding template for different field signals (such as DC or AC, switching, digital or analog, voltage or current, etc.), and can be directly connected to industrial field equipment (such as buttons, switches, inductive current transmitters, motor starters or control valves, etc.). It is connected to the CPU motherboard via a bus.

In addition, the controller has a digital input module, which is an electronic device for connecting external mechanical contacts and electronic digital sensors, and is part of the PLC (Programmable Logic Controller) control system. The main function of the digital input module is to convert the digital signal outside the field to the PLC internal signal level, and transmit it to the CPU for program processing. Digital input modules usually have input channels for receiving external switching quantities or digital signals, such as switching on and off, button pressing, sensor signals, etc. The input circuit is usually equipped with an RC filter circuit to prevent incorrect input signals caused by input contact jitter or external interference pulses.