David, If you are writing in HP C, don't forget #pragma intrinsic HPCIPUTVAR !!! Here is a code snippet from a test program: #pragma intrinsic HPCIPUTVAR /*-------------------------------------------------------------------------*/ /* this procedure is called by test programs. it calls HPCIPUTVAR to set */ /* CI variable to the passed int value. */ /*-------------------------------------------------------------------------*/ void Put_Int_Var(char *varname, int value) { /* Put_Int_Var */ hpe_status status; unsigned keyword; int keyvalue; keyword = 1; /* integer value to be assigned */ keyvalue = value; HPCIPUTVAR(varname, &status, keyword, &keyvalue); if (status.all != 0) log_err_status("HPCIPUTVAR in Put_Int_Var", status); } /* Put_Int_V */ Put_Int_Var("PPXES10N", 127); Steve