matlab udp怎么用 急啊

[wjabcjw]

我在同一台电脑上这样用的，可是收不到
提示：
Warning: The specified amount of data was not returned within the Timeout period.

ans =

Empty matrix: 1-by-0

高手指点啊:cry:
u1 = udp('192.168.6.6',3333,'LocalPort',3332)
fopen(u1)
pause(1);
fwrite(u1,'Ready for data transfer.')
fclose(u1);
delete(u1);
clear u1;


u2 = udp('192.168.6.6',3332,'LocalPort',3333)
fopen(u2)
fread(u2)
fclose(u2);
delete(u2);
clear u2;