560CMU05  通信单元

控制单元 是计算机网络中负责主机与 终端 之间通信的设备，它 控制 与远端数据设备连接的全部 通信信道 ，实现包括 差错控制 、中断接入控制、确认控制、传输顺序和串并转换等功能。 通信控制单元减少了主机的负荷，大大地提高了主机处理数据的 效率 。 常见的CCU有前端处理机。 通信控制单元在硬件上由主控框构成。 主控框在物理上占用两个标准机框的位置，其主要单板包括二次电源板PWC、通信主节点板NOD、双机倒换板EMA、主处理机板MPU、时钟驱动板CKV、交换网板BNET、存储板MEM、多频互控板MFC、协议处理板LAP、告警板ALM、信号音板SIG、模块通信处理板LPMC2、光纤通信板OPT等，

A control unit is a device in a computer network responsible for communication between hosts and terminals. It controls all communication channels connected to remote data devices, achieving functions such as error control, interrupt access control, confirmation control, transmission sequence, and serial parallel conversion. The communication control unit reduces the load on the host and greatly improves the efficiency of the host in processing data. Common CCUs include front-end processors. The communication control unit is composed of a main control frame in hardware. The main control frame physically occupies the position of two standard frames. Its main boards include the secondary power board PWC, the communication main node board NOD, the dual machine switchover board EMA, the main processor board MPU, the clock driver board CKV, the switch network board BNET, the memory board MEM, the multi frequency mutual control board MFC, the protocol processing board LAP, the alarm board ALM, the signal sound board SIG, the module communication processing board LPMC2, the optical fiber communication board OPT, etc,