Number to binary

[nickdiamond]

i want to send 8 bit nos. 0-255 to serial in binary form. When i tried
to type "250" to the write buffer of VISA write, the vi seems to treat
the no. 250 as three no. 2,5 and 0.
All i want is when i send "250" to VISA write, the vi will convert it
as 11111010 to serial port (1 byte)
Please help.
Thank you very much