public bool DisconnectTestModbus(Behavior behavior) { testConnection = new TestModbusTCPConnection(behavior, "172.19.103.8"); WTXModbusObj = new WtxModbus(testConnection, 200); WTXModbusObj.Connect(this.OnConnect, 100); Thread.Sleep(1000); // Do something.... and disconnect. WTXModbusObj.Disconnect(this.OnDisconnect); return(WTXModbusObj.isConnected); // Alternative : Assert.AreEqual(WTXModbusObj.isConnected, true); }