spd 6531 drivers problem

when i try to read info from 6531 always getting

Initializing…
DA_LIB_VER_5.9.0.0
Auto reset and search the USB-to-Serial…
Spd USB-to-Serial not found


i tried latest version of avator software also.. 7.901
i have installed prolic usb to serial comm port .. my cables are good.
i can do this task using volcano box without any error. and using same cables.

if you have latest spd drivers please give me. or give me solution for this problem.