- 24 -6.2.2. ZupClose FunctionClose the USB port and execute driver termination processing. Format Visual C/C++long Ret;Ret = ZupClose(); Visual BasicDim Ret As LongRet = ZupClose() ArgumentHone Return valueRet : End : 0Can not close : other than 0 Setting example Visual C/C++long Ret;Ret = ZupClose(); Visual BasicDim Ret As LongRet = ZupClose()