modbus.go

package modbus

import (
	"encoding/hex"
)

const (
	//Bit 操作

	// FuncCodeReadDiscreteInputs 功能码:读离散量输入
	FuncCodeReadDiscreteInputs = 2
	// FuncCodeReadCoils 功能码:读线圈
	FuncCodeReadCoils = 1
	// FuncCodeWriteSingleCoil 功能码:写单个线圈
	FuncCodeWriteSingleCoil = 5
	// FuncCodeWriteMultipleCoils 功能码:写多个线圈
	FuncCodeWriteMultipleCoils = 15

	//16-bit 操作

	// FuncCodeReadInputRegisters 功能码:读输入寄存器
	FuncCodeReadInputRegisters = 4
	// FuncCodeReadHoldingRegisters 功能码:读保持寄存器
	FuncCodeReadHoldingRegisters = 3
	// FuncCodeWriteSingleRegister 功能码:写单个寄存器
	FuncCodeWriteSingleRegister = 6
	// FuncCodeWriteMultipleRegisters 功能码:写多个寄存器
	FuncCodeWriteMultipleRegisters = 16
	// FuncCodeReadWriteMultipleRegisters 功能码:读/写多个寄存器
	FuncCodeReadWriteMultipleRegisters = 23
)
const (
	TCP   = ModbusMode("TCP")
	RTU   = ModbusMode("RTU")
	ASCII = ModbusMode("ASCII")
)

var (
	faults = map[byte]string{
		1:  "01:illegal function code",
		2:  "02:illegal data address",
		3:  "03:illegal data value",
		4:  "04:slave station equipment is faulty",
		5:  "05:confirm",
		6:  "06:slave device busy",
		8:  "08:store parity errors",
		10: "0A:gateway path is unavailable",
		11: "0B:gateway target device fails to respond",
	}
)

type ModbusMode string

// ProtocolDataUnit 协议数据单元
type ProtocolDataUnit interface {
	GetFunctionCode() (f byte)
	Length() (l int)
	GetData() (data []byte)
	ToHex() (h string)
}

// 协议数据单元
type protocolDataUnit struct {
	functionCode byte
	data         []byte
	length       int
}

func (pdu protocolDataUnit) GetFunctionCode() (f byte) {
	return pdu.functionCode
}

func (pdu protocolDataUnit) Length() (l int) {
	return pdu.length
}
func (pdu protocolDataUnit) GetData() (data []byte) {
	return pdu.data
}
func (pdu protocolDataUnit) ToHex() (h string) {
	return hex.EncodeToString(pdu.data)
}

// ApplicationDataUnit 应用数据单元
type ApplicationDataUnit interface {
	GetSlaveId() byte
	GetFunctionCode() byte
	GetPDU() ProtocolDataUnit
	ToHex() string
	GetData() []byte
	Length() int
	GetCheckSum() uint16
	GetCheckSumByte() []byte
	GetMode() ModbusMode
}

type applicationDataUnit struct {
	slaveID      byte
	pdu          ProtocolDataUnit
	data         []byte
	length       int
	checkSum     uint16
	checkSumByte []byte
	mode         ModbusMode
}

func (u applicationDataUnit) GetSlaveId() byte {
	return u.slaveID
}
func (u applicationDataUnit) GetFunctionCode() byte {
	return u.pdu.GetFunctionCode()
}
func (u applicationDataUnit) GetPDU() ProtocolDataUnit {
	return u.pdu
}
func (u applicationDataUnit) Length() int {
	return u.length
}

func (u applicationDataUnit) ToHex() string {
	return hex.EncodeToString(u.data)
}
func (u applicationDataUnit) GetData() []byte {
	return u.data
}
func (u applicationDataUnit) GetCheckSum() uint16 {
	return u.checkSum
}
func (u applicationDataUnit) GetCheckSumByte() []byte {
	return u.checkSumByte
}

func (u applicationDataUnit) GetMode() ModbusMode {
	return u.mode
}

// Packager 包解析器
type Packager interface {
	Encode(pdu protocolDataUnit) (adu ApplicationDataUnit, err error)
	Decode(results []byte) (adu ApplicationDataUnit, err error)
	Verify(aduRequest ApplicationDataUnit, aduResponse ApplicationDataUnit) (err error)
}

// Transporter 数据传输器
type Transporter interface {
	Open() error
	Connected() bool
	Send(aduRequest ApplicationDataUnit) (aduResponse []byte, err error)
	Close() error
}