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))