通过列车中央控制单元CCU的接口模块（RS232或其他标准接口），用PTU可以访问牵引控制单元DCU，读取故障数据，也可读取DCU内部数据，调整相关数值。DCU中应设置一个接口，该接口能将重要的信号连到该接口上，该接口必须是标准的接口，可以连接一个故障记录插件，记录跟踪故障。在DCU内部的存储区域分为正常记录区，故障记录区。故障记录区分3个记录段，每段必须能记录10分钟的记录，一旦发生故障或紧急制动，即可将正常记录区的靠近故障点的1分钟内的记录完全复制到故障记录区。故障记录区将完整记录最后3个故障的记录。具体的记录信号和采样时间应在详细设计时与用户讨论，并最后应提供给用户这些信号在接口上的位置和内容的清单。
The fault data and internal data of DCU can be read by accessing the DCU by PTU through the interface module of CCU (RS232 or other standard interfaces).  There shall be a standard interface in DCU, which is for transmitting important signals and connecting a plug-in unit for fault logging and tracking.  The memory area in DCU can be divided into normal logging area and fault logging area.   There shall be three record sections in fault logging area, each section can record data for 10 minutes. Once there is a fault or emergency braking, the fault logging area will be completely updated by the records in one minute from the fault point in normal logging area.  The data about the last three faults will be completed recorded in fault logging area.  During design, the specific write signals and sampling time shall be discussed with customer, then provide the customer with detailed description of positions on interface and contents list of these signals.

华译网北京翻译公司翻译过大量有关中央控制单元的文件资料。
Beijing Mandarin Chinese Translation Service Company has translated many technical documents in the field of Central control unit.

故障记录插件：该故障记录插件用于跟踪车辆活故障，它应能通过地面专用软件设定各触发条件，当触发条件满足时跟踪记录各参数，状态信息，该插件所存数据在任何情况下应能至少保存3个月，并配置6个。为进一步的分析车辆状态提供具体参数。该插件容量至少128MB，采用PCMCIA的卡式存储介质。并提供专用的分析软件对数据进行分析。对该软件应提供可拷贝的光碟。
Plug-in units for fault logging: they are used for tracking information about all parameters and states of active faults when triggering conditions are set by special software on ground. They shall be able to keep the recorded data for at least 3 months.  In order to provide specific parameters for analyzing the running state of train, there shall be 6 plug-in units.  The capacity of each plug-in unit shall be at least 128MB, and the card storage medium specified by PCMCIA is used. In addition, special software and copy CD shall be provided for data analysis.