not able to make connection with zkteco multibio 700 device

Question

public bool Connect_Net(string IPAdd, int Port)
{
if (objCZKEM.Connect_Net(IPAdd, Port))
{
//65535, 32767
if (objCZKEM.RegEvent(1, 65535))
{
// [Register your events here]
//[Go through the _IZKEMEvents_Event class for a complete list of events
objCZKEM.OnConnected += ObjCZKEM_OnConnected;
objCZKEM.OnDisConnected += objCZKEM_OnDisConnected;
objCZKEM.OnEnrollFinger += ObjCZKEM_OnEnrollFinger;
objCZKEM.OnFinger += ObjCZKEM_OnFinger;
objCZKEM.OnAttTransactionEx += new _IZKEMEvents_OnAttTransactionExEventHandler(zkemClient_OnAttTransactionEx);
}
return true;
}
return false;
}

this is my code but i m not able to make connection with device