ThingsBoard网关之ModbusRPC请求

发布日期: 2020-06-19

之前模拟了Modbus设备的数据采集，这次来模拟下Modbus下的RPC请求。

1.模拟一个空调设备，采用ModbusTCP

使用ModbusSlave模拟设备，设备地址1，分配4个寄存器：

寄存器1:模式
寄存器2:开关状态
寄存器3,4:温度（这里用2个寄存器存浮点型数据）

网关配置文件：

{
  "server": {
    "type": "tcp",
    "host": "10.49.0.66",
    "port": 502,
    "timeout": 35,
    "method": "socket",
    "byteOrder": "BIG",
    "devices": [
     {
        "unitId": 1,
        "deviceName": "CountSensor",
        "attributesPollPeriod": 5000,
        "timeseriesPollPeriod": 5000,
        "sendDataOnlyOnChange": true,
        "timeseries": [
          {
            "byteOrder": "BIG",
            "tag": "count",
            "type": "16int",
            "functionCode": 3,
            "objectsCount": 1,
            "address": 0
          },
          {
            "byteOrder": "BIG",
            "tag": "status",
            "type": "16int",
            "functionCode": 3,
            "objectsCount": 1,
            "address": 1
          },
          {
            "byteOrder": "BIG",
            "tag": "temperature",
            "type": "32float",
            "functionCode": 3,
            "objectsCount": 2,
            "address": 2
          }
        ],
        "rpc": [
          {
            "tag": "setValue",
            "type": "16int",
            "functionCode": 6,
            "objectsCount": 1,
            "address": 1
          },
          {
            "tag": "getValue",
            "type": "16int",
            "functionCode": 3,
            "objectsCount": 1,
            "address": 1
          },
          {
            "tag": "setTemperature",
            "type": "32float",
            "functionCode": 6,
            "objectsCount": 2,
            "address": 2
          },
          {
            "tag": "getTemperature",
            "type": "32float",
            "functionCode": 3,
            "objectsCount": 2,
            "address": 2
          }
        ]
      }
    ]
  }
}

2.打开ModbusSlave的Connection，启动网关

可以看到设备数据已经上来：

3.创建仪表盘

先新建一个实体设备，指向CountSensor。添加开关控件及数值控件。
注意控件中的高级设置，Rpc get value method，Rpc set value method的值要与网关中rpc配置方法名一致。

整个仪表盘如下图：

4.控制模拟

点击开关控制Round Switch，可看到仪表盘状态值的改变

控制温度，发现没有效果，查看网关日志，发现如下错误：

""2020-06-19 10:15:09" - ERROR - [modbus_connector.py] - modbus_connector - 290 - required argument is not a float"
Traceback (most recent call last):
File "D:\ProgramFilesData\Motrix\thingsboard-gateway-2.3.1.1\thingsboard_gateway\connectors\modbus\modbus_connector.py", line 278, in server_side_rpc_handler
 self.__process_rpc_request(content, rpc_command_config)
File "D:\ProgramFilesData\Motrix\thingsboard-gateway-2.3.1.1\thingsboard_gateway\connectors\modbus\modbus_connector.py", line 298, in __process_rpc_request
 rpc_command_config["payload"] = self.__devices[content["device"]]["downlink_converter"].convert(
File "D:\ProgramFilesData\Motrix\thingsboard-gateway-2.3.1.1\thingsboard_gateway\connectors\modbus\bytes_modbus_downlink_converter.py", line 75, in convert
 builder_functions[lower_type](value)
File "D:\ProgramFiles\Python\Python38\lib\site-packages\pymodbus\payload.py", line 251, in add_32bit_float
 p_string = self._pack_words(fstring, value)
File "D:\ProgramFiles\Python\Python38\lib\site-packages\pymodbus\payload.py", line 79, in _pack_words
 value = pack("!{}".format(fstring), value)
struct.error: required argument is not a float

报错说传入的参数不是一个float值，于是我重新控制，在网关中断点看到了传入的参数是一个str：

应该是上层的问题,于是查看下控制请求的参数，发现传参时就是个str：

找到问题那就好改了，在knob.directive.js中将控件值转成float:

function turn(ratio) {
        var value = (vm.minValue + (vm.maxValue - vm.minValue)*ratio).toFixed(vm.ctx.decimals);
        if (canvasBar.value != value) {
            canvasBar.value = value;
        }
        updateColor(canvasBar.getValueColor());

        value = parseFloat(value);
        onValue(value);
    }