东黄线再接终端系统的开发和研制

Developing the Second-joint Video Terminal System for Dong-Huang Oil Pipeline

为解决东黄线全线现场运行情况监视、运行状态汉字显示、屏幕硬拷贝等问题,开发和研制了东黄线再接终端系统。该系统有两台VAX主机,通过RS—232通信口与S/3系统的通信转换器相连,再经调制解调器与前置通信机相连,通过网络服务器实现文件共享。再接终端系统与VAX机通信协议采用对每一个要传输的数据进行打包传送的协议规程,并确定最佳通信速率为2400 bit/s。现场运行实验证明:连入再接终端系统后,两台VAX主机可以实现热备切换,而且其数据库当前值保持一致。实现了中文显示、黑白和彩色屏幕拷贝、报警条显示,同屏8条趋势曲线显示等功能。

The second-joint video terminal system for Dong-Huang Oil Pipeline has been developed in order to improve the line's field operating supervisory, field operating status, display of Chinese characters and screen copying. This system,being two VAX I hosts designed,respectively connects with communication transfer switch of S/3 system via RS-232 port and with communication concentrated module through modem. The communication network server can achieve the function of all files-in-share. For data transmission, the system's host uses the protocol of package & unpackage,and its best communication band rate is defined as 2 400 bit/s. The field operation results show that the two VAX II hosts can be switched to another automatically in 'hot condition' after the new system has been put into operation, and all data in them can be refreshed at the same time. It brings about the following functions; Chinese display, monochrome and/or color screen copying, alarm-pieces display and eitht-trend curves display on one screen.