目前，我国大多数轨道列车逻辑控制系统都采用有触点的控制方式，随着对列车性能要求的提高，这种有触点控制方式暴露出电路结构复杂、可靠性与灵活性差等一系列弊端。

    逻辑控制单元LCU(Logic Control Unit)使用现代化的电子元件来取代原来电力机车上由电磁线圈和机械触点构成的继电器。相比传统的列车控制电路，LCU控制电路采用完全的双冗余设计，大幅度地提高了系统可靠性和响应速度；此外还增加了故障记录单元，提供全程的故障实时记录，有助于维护人员快速维修和维护；上位机软件可以随时更改逻辑设计，如果有控制逻辑或者延时参数等修改的需求，重新下载一遍控制逻辑即可，无需更换硬件设备或者重新布线；产品还增加了紧急环路开关模块，一旦出现极端的故障情况，也不会导致列车控制严重瘫痪。

    综上，以逻辑控制网络来替代原有的逻辑电路是未来列车逻辑控制电路的发展趋势。LCU可以大幅度提高列车控制电路的整体可靠性，降低车辆维护难度，减少检修工作量，从而实现列车车辆控制电路系统技术的升级。

    At present, most of domestic railway logic control system uses relay control mode，as the improvement requirements of train performance, relay control mode exposes a series of drawbacks such as over complicated circuit structure, poor reliability and poor flexibility.

    The logic control unit (LCU) use modern electronic components to replace the original electric locomotive composed of electromagnetic coil and mechanical relay. Compared with the traditional train control circuit, LCU uses full dual redundancy design, greatly improved the reliability and response speed of system;embedded a fault recording unit, providing fault real-time recording of the entire process which is helpful to a quick repairment and maintenance; PC software can change the logic design at any time, if there is a delay or parameter needs to modify such as demand, all you need is download it again ,no need to change the hardware devices or rewiring; the product also embedded the emergency loop switch module , once comes to a extreme failure, it will not lead to a serious train control paralysis.

    In summary, logical control networks replace the original logic circuit is the  trend of future train logic control circuit . LCU can greatly improve the reliability of the whole train control circuit, reduce vehicle maintenance difficulty, reduce maintenance workload, so as to realize the upgrade of train circuit control system .