i write "viWrite(instr,"ISET 3.0",8,&m_retCount)" in vc++6.0,but when i build this project,some error occur.the error message is cannot convert parameter 2 from 'char *' to 'unsigned char *' Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast. Why? VC++6.0 with sp5, winXP, NI-VISA 2.5.