I am trying to use vee to control RS-232 instrument. I connect the equipment and PC through a RS-232 to USB cable. I have successed in controling the equipment with Serial debugging assistant but when I try to control the equip with VEE ,I found there is yellow question mark in the instrument manager and there was no respons to *IDN? ,Maybe the equipment self can not recognize the order? But how to control such equipment with VEE? Is there someone can help me.