485通信程序 对主机从机通信协议规定其通信方式 对帧的传送有严格定义-Communication program on the host 485 communication from the communication protocol provides for the transmission of the frame there is a strict definition of
多点GPS与超图的VB开发程序的应用,对地理信息系统开发有益-Multi-point GPS hypergraph of VB and the development of procedures for the application of geographic information system development useful