config multiport serial card

[s m]

hello everybody

i have a moxa 4-port serial card and installed it on freebsd8.2
successfully. i have ttyu2-5 in /dev that are moxa ports.

my question is how i can use these ports? i add the following lines to ttys
file:
ttyu2 "/usr/libexec/getty std.9600" vt100 on secure
ttyu3 "/usr/libexec/getty std.9600" vt100 on secure
ttyu4 "/usr/libexec/getty std.9600" dialup on secure
ttyu5 "/usr/libexec/getty std.9600" dialup on secure

and restart my system. i connect another system to one of my moxa port by a
null modem cable and run putty in both side but i can't see any thing in
putty screens and leds on moxa card doesn't turn on.

please let me know if i should do some configuration else in order to my
ports work correctly. should i use another application instead of putty to
work with these ttyus?

thanks
sam