By looking at following code statements, unsigned char response[20] ; UINT *rspSize; rspSize = (PUINT)malloc(sizeof(UINT)); result = ezLinkRcv(response,rspSize); it seems like problem with rspSize, rspSize doesn't match with response memory allocatin i.e. 20. I suggest you to try out giving hard-coded 20 instead of rspSize to know exact problem and then after implement generalized logic.

Did you get a solution to the issues you have been having with the EZCDM1000. I am looking to control it through VB.net also. Any tips ?

thanks for the help guys. I think my first step is going to be finding a .h I think after that and all your advice I can get it done. augie