接线端子（可选）

接线端子是用于在控制柜（尤其是PLC机架）中端接和连接多根电线的机电元件。它们由绝缘体（通常为塑料）和导电金属端子（螺钉式、弹簧式或直插式）组成，可牢固夹紧电线。在PLC系统中，它们作为现场设备（传感器、执行器）与PLC的I/O模块之间的接口点，实现有序、可靠的接线，且无需焊接即可轻松维护。

接线端子通过提供机械夹紧机构（通过螺钉、弹簧或杠杆）将剥去绝缘层的电线端部压在导电金属端子上，从而形成低电阻电气连接。绝缘体防止相邻端子之间以及对接地发生短路。在PLC机架中，它们将现场接线的信号传输至PLC的输入/输出卡，实现集中控制和监控。

Terminal blocks work by providing a mechanical clamping mechanism (via screws, springs, or levers) that holds stripped wire ends against a conductive metal terminal. This creates a low-resistance electrical connection. The insulating body prevents short circuits between adjacent terminals and to ground. In PLC racks, they channel signals from field wiring to the PLC's input/output cards, enabling centralized control and monitoring.