EXTERNAL:

Keyword to declare a subprogram with

parameter transfer.

note:

You only have to specify EXTERNAL if the

subprogram is in the workpiece or in the

global subprogram directory. Cycles do

not have to be declared as

Keyword to declare a subprogram with

parameter transfer.

说得很清楚:1.调用的是带参数的子程序

2.子程序不在循环(用户/制造商/标准循环)目录中时

调用它才加必须加EXTERNAL

所以几乎没见过用EXTERNAL,因为绝大多数带参数的子程序都放在循环目录中的,任何程序都直接调用它.<