在利用单板机进行工业控制时,有时一合单板机不能较好地完成任务,这时可以采用两台或三台联合工作。对于Z80单板机,实现双机联合的方法比较多见。这里给出一种三台Z80单板机的联机系统硬件逻辑。系统采用了PIO并行通讯。由于主机也用单板机,故本系统可用于一些要求不是很高的场合。本系统属于主从式多机系统。两台从机间的通讯,要经过主机才能完成。主机可同时向两台从机发送相同的数据。每台单板机有一片PIO用于通讯。单板机间的最大通讯距离为2～4米。主从机间的通讯数据率为160K波特。而 In the use of single-board industrial control, and sometimes a single board machine can not do the task well, then you can use two or three joint work. For the Z80 single board machine, to achieve more common dual-machine approach. Here is a three-Z80 single-board machine online system hardware logic. The system uses PIO parallel communication. Since the host is also a single board machine, so the system can be used for some not demanding occasions. The system belongs to master-slave multi-machine system. Two from the machine communication, to go through the host to complete. The host can send the same data to both slaves at the same time. Each SBC has a PIO for communication. The maximum communication distance between single board machine is 2 ~ 4 meters. Master and slave communication data rate of 160K baud. and