一、引言目前,计算机控制与监测系统一般采用单级或多级结构,两级系统正由集中式向分布式发展。国内纺织业织机监测计算机系统多采用“系统机-单板机”结构形式,机间通讯则选用并行接口(如Z80-PIO)来实现。这种方式的优点是通讯速率高,但需配置的传输线数量多,传输距离有限。如果要实现多机通讯,必须在通讯接口外添加多路选择控制装置,而这样却提高了硬件费用。为降低装置成本,减少传输线数量,提高可靠性,我们开发了“ - I. INTRODUCTION At present, computer control and monitoring systems generally adopt single-stage or multi-stage structure, and the two-stage system is being developed from centralized to distributed. Domestic textile loom monitoring computer systems to use more “system machine - single board machine” structure, machine communication is the choice of parallel interface (such as Z80-PIO) to achieve. The advantage of this method is that the communication speed is high, but the number of transmission lines to be configured is large and the transmission distance is limited. If you want to achieve multi-machine communication, must add multiple choice control device outside the communication interface, but this has raised the hardware cost. To reduce equipment costs, reduce the number of transmission lines and improve reliability, we have developed "-