edgeXFoundry中modbus通信部署和测试（待续）

modbus协议分为基于tcp/ip的modbus tcp和和基于RS485接口的modbus rtu两种通信方式。

modbus方式虚拟设备部署测试

如下：参阅：https://docs.edgexfoundry.org/1.2/examples/Ch-ExamplesAddingModbusDevice/

1. 首先登录控制台edgex-ui-go页面，导入device profile文件，和mqtt导入相同。文件名为modbus.device.profile.yml。内容如下：

name: "Network Power Meter"
manufacturer: "Dent Instruments"
model: "PS3037"
description: "Power Scout Meter"
labels:
  - "modbus"
  - "powerscout"
deviceResources:
  -
    name: "Current"
    description: "Average current of all phases"
    attributes:
      { primaryTable: "HOLDING_REGISTERS", startingAddress: "9" }
    properties:
      value:
        { type: "UINT16", scale: "1"}
      units:
        { type: "String", readWrite: "R", defaultValue: "min"}
  -
    name: "Energy"
    description: "System Total True Energy"
    attributes:
      { primaryTable: "HOLDING_REGISTERS", startingAddress: "4001" }
    properties:
      value:
        { type: "FLOAT32", scale: "1"}
      units:
        { type: "String", readWrite: "R", defaultValue: "min"}
  -
    name: "Power"
    description: "System Total True Power "
    attributes:
      { primaryTable: "HOLDING_REGISTERS", startingAddress: "4003" }
    properties:
      value:
        { type: "UINT16", scale: "1"}
      units:
        { type: "String", readWrite: "R", defaultValue: "min"}
  -
    name: "Voltage"
    description: "Voltage Line to line (Volts) Average"
    attributes:
      { primaryTable: "HOLDING_REGISTERS", startingAddress: "4017" }
    properties:
      value:
        { type: "UINT16", scale: "1"}
      units:
        { type: "String", readWrite: "R", defaultValue: "min"}
  -
    name: "DemandWindowSize"
    description: "Demand window size in minutes; default is 15 min"
    attributes:
      { primaryTable: "HOLDING_REGISTERS", startingAddress: "4603" }
    properties:
      value:
        { type: "UINT16", readWrite: "R", scale: "1"}
      units:
        { type: "String", readWrite: "R", defaultValue: "min"}
  -
    name: "LineFrequency"
    description: "Line frequency setting for metering: 50=50 Hz, 60=60Hz"
    attributes:
      { primaryTable: "HOLDING_REGISTERS", startingAddress: "4609" }
    properties:
      value:
        { type: "UINT16", readWrite: "R", scale: "1"}
      units:
        { type: "String", readWrite: "R", defaultValue: "Hz"}
deviceCommands:
  -
    name: "Current"
    get:
      - { index: "1", operation: "get", deviceResource: "Current" }
  -
    name: "Values"
    get:
      - { index: "1", operation: "get", deviceResource: "Energy" }
      - { index: "2", operation: "get", deviceResource: "Power" }
      - { index: "3", operation: "get", deviceResource: "Voltage" }
  -
    name: "Configuration"
    set:
      - { index: "1", operation: "set", deviceResource: "DemandWindowSize" }
      - { index: "2", operation: "set", deviceResource: "LineFrequency" }
    get:
      - { index: "1", operation: "get", deviceResource: "DemandWindowSize" }
      - { index: "2", operation: "get", deviceResource: "LineFrequency" }
coreCommands:
  -
    name: "Current"
    get:
      path: "/api/v1/device/{deviceId}/Current"
      responses:
        -
          code: "200"
          description: "Get the Current"
          expectedValues: ["Current"]
        -
          code: "500"
          description: "internal server error"
          expectedValues: []
  -
    name: "Values"
    get:
      path: "/api/v1/device/{deviceId}/Values"
      responses:
        -
          code: "200"
          description: "Get the Values"
          expectedValues: ["Energy","Power","Voltage"]
        -
          code: "500"
          description: "internal server error"
          expectedValues: []
  -
    name: "Configuration"
    get:
      path: "/api/v1/device/{deviceId}/Configuration"
      responses:
        -
          code: "200"
          description: "Get the Configuration"
          expectedValues: ["DemandWindowSize","LineFrequency"]
        -
          code: "500"
          description: "internal server error"
          expectedValues: []
    put:
      path: "/api/v1/device/{deviceId}/Configuration"
      parameterNames: ["DemandWindowSize","LineFrequency"]
      responses:
        -
          code: "204"
          description: "Set the Configuration"
          expectedValues: []
        -
          code: "500"
          description: "internal server error"
          expectedValues: []

对要读取的modbus地址和存储的数据类型需要在profile中进行编辑。

2 修改modbus服务端的容器编排文件docker-compose.yml，将以下代码解注释：

然后重新启动：docker-compose up -d。

#  device-modbus:
#    image: edgexfoundry/docker-device-modbus-go:1.2.1
#    ports:
#      - "127.0.0.1:49991:49991"
#    container_name: edgex-device-modbus
#    hostname: edgex-device-modbus
#    networks:
#      - edgex-network
#    environment:
#      <<: *common-variables
#      Service_Host: edgex-device-modbus
#    depends_on:
#      - data
#      - command

　　

3.和MQTT方式相同，在服务下添加设备，配置地址和端口，获得最终的控制台界面：

4.配置虚拟modebus设备。下载软件中的jar包，打开，点击Add，为方便测试，默认全选即可，其他不需要配置。然后点击Run。

http://modbuspal.sourceforge.net/

5.在控制台点击Send，获取结果，观察结果。另外，其中的Float32的Base64编码结果测试结果如下：

原始结果先解码，然后将byte数组所有表示为16进制，变成4个字节。其中高位两个字节表示为读取单位的值（INT），最大到0x7F7F，低位两个字节表示为读取位置的下一个位置的值。

当值超出范围或者仿真设置不正确时，Send返回结果会报错。

附上Python解码Base64并全体16进制显示的脚本：

import base64
bytes = base64.b64decode("f38AAA==")
l = [hex(int(i)) for i in bytes]
print(" ".join(l))