船舶主机监测报警系统计算机通信电路的实现

船舶机舱网络式主机监测报警系统的核心部件是主机通信板 ,在通信网络中起主机 (主站 )作用 ,以接口卡的形式插在计算机ISA插槽中。主机通信板由CPU、RS - 4 85通信电路、双口RAM和ISA总线接口部分组成。其中RS - 4 85通信电路作为主机与信号采集器进行串行通信 ,CPU将接收到的数据不经处理放入双口RAM指定的内存地址中 ,ISA总线接口将计算机发出的寻址信息译成对双口RAM的寻址信号 ,从而实现RAM的共享。所设计的主机通信板在船舶机舱使用性能稳定、效果良好 。

The core component of the network type of engine inspecting and alarming system in ship′s engine room is communication board. It acts as the mainframe in the communication net. Inserted into the ISA plug, the board is composed with CPU?RS-485 communication circuit? double channel RAM and total line of ISA. RS-485 communication circuit in the communication board is used as a string line connector between the mainframe and sign collector. CPU transfers the data signals to the EMS memory appointed by the double channel RAM. ISA translates the address seeking signal which comes from computer into the RAM address seeking signal. Then the RAM is shared. The function of communication board designed is properly. Used in the ships engine room, the board is reliable and effective. It can satisfy the requirement in working process very well.