FTP Error Code 600

Dear All
recently I met with an issue that when our webmethods’ procedure trying to login FTP site ,it returns 600.
I searched in google website,but cann’t find FTP return code for 600.So I wander if this return code is for webmethods only and what this return code means. Could anyone help me out of this problem,thank you very much!
conio
2009/07/31

What is that you were trying to accomplish, can you please be more specific with respect to the task you were trying to accomplish with respect to ftp.