Have you looked at MSKB#Q154741 ?

>>Hi David
>>
>>If CHR(i) bigger 128 than receive the data is 0
>
>Hi Liu
>
>>Maybe you need to set InputMode to binary mode
>>mscomm.olemscomm.object.InputMode = 1 && Binary mode
>>Herman
>
>
>Yes I need receive binary data
>But Mscomm control doesn't send binary Data,if send bigger 128 than receive to 0