ModbusORM

Object Relational Mapping (ORM) for Modbus

What is ModbusORM

ModbusORM is a golang package allows you to read/write Modbus data by struct with tag (morm).

Usage

• Define the points

  // modbusorm.Point is a map with string key and modbusorm.PointDetails value.
  // key is the point name, which will be used in tag (morm)
  point := modbusorm.Point{
  	"voltage": modbusorm.PointDetails{
  		// Address of this point.
  		Addr: 100,
  		// Quantity of this poiont.
  		Quantity: 1,
  		// Coefficient of this point. Default 1.
  		// For example:
  		//      if read 10 from modbus server,
  		//      and coefficient is 0.1,
  		//      then you will get 1 in result.
  		Coefficient: 0.1,
  		// Data type of this point
  		//      U16, S16, U32, S32
  		DataType: modbusorm.PointDataTypeU16,
  	},
  }
  

• Define a struct with morm tag.

  type Data struct {
      Voltage     *float64             `morm:"voltage"`
      Temperature float64              `morm:"temperature"`
      Star        []float64            `morm:"star"`
      Origin      modbusorm.OriginByte `morm:"origin"`
      Word        string               `morm:"word"`
      Unknown     *float64             `morm:"unkonwn"`
  }
  

• Read/Write with your modbus server.

  // new
  conn := modbusorm.NewModbusTCP(
  	// Host of modbus server.
  	"localhost",
  	// Port of modbus server.
  	1502,
  	// Point define before.
  	point,
  	// Block mode setting. Default false.
  	//  With block mode, ModbusORM will try to read data by block,
  	//  rather than by single point.
  	//  If set to true, two more parameters is avaliable.
  	modbusorm.WithBlock(true),
  	// Max block size. Default 100.
  	//  Only work with block mode.
  	modbusorm.WithMaxBlockSize(100),
  	// Max gap in block. Default 10.
  	//  Only work with block mode.
  	modbusorm.WithMaxGapInBlock(10),
  	// timeout setting.
  	modbusorm.WithTimeout(10*time.Second),
  	// max open connections in connection pool.
  	modbusorm.WithMaxOpenConns(3),
  	// max connection lifetime in connection pool.
  	modbusorm.WithConnMaxLifetime(30*time.Minute),
  )
  // connect
  conn.Conn()
  // read
  data := &Data{}
  conn.GetValues(context.Background(), data)
  

• See more details in _example

Demo

• Modbus TCP
  • go to example folder: cd _example/modbus_tcp
  • start a demo server: go run server.go
  • start a demo client: go run client.go

TODOs

• README
• Modbus RTU
• Example
• More data type
• Logger