/**
     * 获取 Modbus Master
     *
     * @param deviceId
     * @param driverInfo
     * @return
     * @throws ModbusInitException
     */
    public ModbusMaster getMaster(Long deviceId, Map<String, AttributeInfo> driverInfo) throws ModbusInitException {
        log.debug("Modbus Tcp Connection Info {}", JSON.toJSONString(driverInfo));
        ModbusMaster modbusMaster = masterMap.get(deviceId);
        if (null == modbusMaster || !modbusMaster.isConnected()) {
            IpParameters params = new IpParameters();
            params.setHost(attribute(driverInfo, "host"));
            params.setPort(attribute(driverInfo, "port"));
              //此处设置keepAlive 为true貌似无效
              // 所以每次都会重新连接，在连接实际设备时
            modbusMaster = modbusFactory.createTcpMaster(params, true);
            modbusMaster.init();
           // 此处输出modbusMaster.isConnected() false
            System.out.println("状态："+modbusMaster.isConnected()); 
           //增加 手动置位
            modbusMaster.setConnected(true);
            masterMap.put(deviceId, modbusMaster);
        }
        return modbusMaster;
    }