A function terminal requiring an input is unwired. You cannot leave unwired functions on the diagram while you run a VI to try out different algorithms.

一个必需连接函数接有连。不能再程序框图中放置一个未连函数，若运行VI会造成一个错误算法。

It is a difficult thing for our student to draw a block digram according to a principle digram,the difficulties are analysed and some good methods are also given in this article.

以一道题为例，对绘制框图时几个难点进行了较深入分析，给出了克服困难法.