说明：  vb6.0环境下pc与plc的通信。Visual Basic,简称VB，是Microsoft公司推出的一种Windows应用程序开发工具。是当今世界上使用最广泛的编程语言之一，它也被公认为是编程效率最高的一种编程方法。
(VB6.0 environment pc and plc communication. Visual Basic, referred to as VB, is the Microsoft Corporation to launch a Windows application development tools. Is the world s most widely used programming languages, it also is recognized as the most efficient programming a programming method.)