evcc-io/util/modbus/modbus.go
2021-09-08 09:54:10 +02:00

349 lines
9.6 KiB
Go

package modbus
import (
"errors"
"fmt"
"strconv"
"strings"
"time"
"github.com/evcc-io/evcc/util"
"github.com/volkszaehler/mbmd/meters"
"github.com/volkszaehler/mbmd/meters/rs485"
"github.com/volkszaehler/mbmd/meters/sunspec"
)
// WriteSingleRegister 16-bit wise write access
const WriteSingleRegister = 6 // modbus.FuncCodeWriteSingleRegister
type WireFormat int
const (
TcpFormat WireFormat = iota
RtuFormat
AsciiFormat
)
// Settings contains the ModBus settings
type Settings struct {
ID uint8
SubDevice int
URI, Device, Comset string
Baudrate int
RTU *bool // indicates RTU over TCP if true
}
// Connection decorates a meters.Connection with transparent slave id and error handling
type Connection struct {
slaveID uint8
conn meters.Connection
delay time.Duration
}
func (mb *Connection) prepare() {
mb.conn.Slave(mb.slaveID)
if mb.delay > 0 {
time.Sleep(mb.delay)
}
}
func (mb *Connection) handle(res []byte, err error) ([]byte, error) {
if err != nil {
mb.conn.Close()
}
return res, err
}
// Delay sets delay so use between subsequent modbus operations
func (mb *Connection) Delay(delay time.Duration) {
mb.delay = delay
}
// Logger sets logger implementation
func (mb *Connection) Logger(logger meters.Logger) {
mb.conn.Logger(logger)
}
// Timeout sets the connection timeout (not idle timeout)
func (mb *Connection) Timeout(timeout time.Duration) {
mb.conn.Timeout(timeout)
}
// ReadCoils wraps the underlying implementation
func (mb *Connection) ReadCoils(address, quantity uint16) ([]byte, error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().ReadCoils(address, quantity))
}
// WriteSingleCoil wraps the underlying implementation
func (mb *Connection) WriteSingleCoil(address, quantity uint16) ([]byte, error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().WriteSingleCoil(address, quantity))
}
// ReadInputRegisters wraps the underlying implementation
func (mb *Connection) ReadInputRegisters(address, quantity uint16) ([]byte, error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().ReadInputRegisters(address, quantity))
}
// ReadHoldingRegisters wraps the underlying implementation
func (mb *Connection) ReadHoldingRegisters(address, quantity uint16) ([]byte, error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().ReadHoldingRegisters(address, quantity))
}
// WriteSingleRegister wraps the underlying implementation
func (mb *Connection) WriteSingleRegister(address, value uint16) ([]byte, error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().WriteSingleRegister(address, value))
}
// WriteMultipleRegisters wraps the underlying implementation
func (mb *Connection) WriteMultipleRegisters(address, quantity uint16, value []byte) ([]byte, error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().WriteMultipleRegisters(address, quantity, value))
}
// ReadDiscreteInputs wraps the underlying implementation
func (mb *Connection) ReadDiscreteInputs(address, quantity uint16) (results []byte, err error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().ReadDiscreteInputs(address, quantity))
}
// WriteMultipleCoils wraps the underlying implementation
func (mb *Connection) WriteMultipleCoils(address, quantity uint16, value []byte) (results []byte, err error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().WriteMultipleCoils(address, quantity, value))
}
// ReadWriteMultipleRegisters wraps the underlying implementation
func (mb *Connection) ReadWriteMultipleRegisters(readAddress, readQuantity, writeAddress, writeQuantity uint16, value []byte) (results []byte, err error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().ReadWriteMultipleRegisters(readAddress, readQuantity, writeAddress, writeQuantity, value))
}
// MaskWriteRegister wraps the underlying implementation
func (mb *Connection) MaskWriteRegister(address, andMask, orMask uint16) (results []byte, err error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().MaskWriteRegister(address, andMask, orMask))
}
// ReadFIFOQueue wraps the underlying implementation
func (mb *Connection) ReadFIFOQueue(address uint16) (results []byte, err error) {
mb.prepare()
return mb.handle(mb.conn.ModbusClient().ReadFIFOQueue(address))
}
var connections = make(map[string]meters.Connection)
func registeredConnection(key string, newConn meters.Connection) meters.Connection {
if conn, ok := connections[key]; ok {
return conn
}
connections[key] = newConn
return newConn
}
// NewConnection creates physical modbus device from config
func NewConnection(uri, device, comset string, baudrate int, wire WireFormat, slaveID uint8) (*Connection, error) {
var conn meters.Connection
if device != "" && uri != "" {
return nil, errors.New("invalid modbus configuration: can only have either uri or device")
}
if device != "" {
switch strings.ToUpper(comset) {
case "8N1", "8E1":
case "80":
comset = "8E1"
default:
return nil, fmt.Errorf("invalid comset: %s", comset)
}
if baudrate == 0 {
return nil, errors.New("invalid modbus configuration: need baudrate and comset")
}
if wire == RtuFormat {
conn = registeredConnection(device, meters.NewRTU(device, baudrate, comset))
} else {
conn = registeredConnection(uri, meters.NewASCII(device, baudrate, comset))
}
}
if uri != "" {
uri = util.DefaultPort(uri, 502)
switch wire {
case RtuFormat:
conn = registeredConnection(uri, meters.NewRTUOverTCP(uri))
case AsciiFormat:
conn = registeredConnection(uri, meters.NewASCIIOverTCP(uri))
default:
conn = registeredConnection(uri, meters.NewTCP(uri))
}
}
if conn == nil {
return nil, errors.New("invalid modbus configuration: need either uri or device")
}
slaveConn := &Connection{
slaveID: slaveID,
conn: conn,
}
return slaveConn, nil
}
// NewDevice creates physical modbus device from config
func NewDevice(model string, subdevice int) (device meters.Device, err error) {
if IsRS485(model) {
device, err = rs485.NewDevice(strings.ToUpper(model))
} else {
device = sunspec.NewDevice(strings.ToUpper(model), subdevice)
}
if device == nil {
err = errors.New("invalid modbus configuration: need either uri or device")
}
return device, err
}
// IsRS485 determines if model is a known MBMD rs485 device model
func IsRS485(model string) bool {
for k := range rs485.Producers {
if strings.ToUpper(model) == k {
return true
}
}
return false
}
// RS485FindDeviceOp checks is RS485 device supports operation
func RS485FindDeviceOp(device *rs485.RS485, measurement meters.Measurement) (op rs485.Operation, err error) {
ops := device.Producer().Produce()
for _, op := range ops {
if op.IEC61850 == measurement {
return op, nil
}
}
return op, fmt.Errorf("unsupported measurement: %s", measurement.String())
}
// Register contains the ModBus register configuration
type Register struct {
Address uint16 // Length uint16
Type string
Decode string
}
// RegisterOperation creates a read operation from a register definition
func RegisterOperation(r Register) (rs485.Operation, error) {
op := rs485.Operation{
OpCode: r.Address,
ReadLen: 2,
}
switch strings.ToLower(r.Type) {
case "holding":
op.FuncCode = rs485.ReadHoldingReg
case "input":
op.FuncCode = rs485.ReadInputReg
case "writesingle":
op.FuncCode = WriteSingleRegister // modbus.FuncCodeWriteSingleRegister
default:
return rs485.Operation{}, fmt.Errorf("invalid register type: %s", r.Type)
}
switch strings.ToLower(r.Decode) {
case "float32", "ieee754":
op.Transform = rs485.RTUIeee754ToFloat64
case "float32s", "ieee754s":
op.Transform = rs485.RTUIeee754ToFloat64Swapped
case "float64":
op.Transform = rs485.RTUUint64ToFloat64
op.ReadLen = 4
case "uint16":
op.Transform = rs485.RTUUint16ToFloat64
op.ReadLen = 1
case "uint32":
op.Transform = rs485.RTUUint32ToFloat64
case "uint32s":
op.Transform = rs485.RTUUint32ToFloat64Swapped
case "uint64":
op.Transform = rs485.RTUUint64ToFloat64
op.ReadLen = 4
case "int16":
op.Transform = rs485.RTUInt16ToFloat64
op.ReadLen = 1
case "int32":
op.Transform = rs485.RTUInt32ToFloat64
case "int32s":
op.Transform = rs485.RTUInt32ToFloat64Swapped
default:
return rs485.Operation{}, fmt.Errorf("invalid register decoding: %s", r.Decode)
}
return op, nil
}
// SunSpecOperation is a sunspec modbus operation
type SunSpecOperation struct {
Model, Block int
Point string
}
// ParsePoint parses sunspec point from string
func ParsePoint(selector string) (model int, block int, point string, err error) {
err = fmt.Errorf("invalid point: %s", selector)
el := strings.Split(selector, ":")
if len(el) < 2 || len(el) > 3 {
return
}
if model, err = strconv.Atoi(el[0]); err != nil {
return
}
if len(el) == 3 {
// block is the middle element
if block, err = strconv.Atoi(el[1]); err != nil {
return
}
}
point = el[len(el)-1]
return model, block, point, nil
}
// Operation is a register-based or sunspec modbus operation
type Operation struct {
MBMD rs485.Operation
SunSpec SunSpecOperation
}
// ParseOperation parses an MBMD measurement or SunsSpec point definition into a modbus operation
func ParseOperation(dev meters.Device, measurement string, op *Operation) (err error) {
// if measurement cannot be parsed it could be SunSpec model/block/point
if op.MBMD.IEC61850, err = meters.MeasurementString(measurement); err != nil {
op.SunSpec.Model, op.SunSpec.Block, op.SunSpec.Point, err = ParsePoint(measurement)
return err
}
// for RS485 check if producer supports the measurement
if dev, ok := dev.(*rs485.RS485); ok {
op.MBMD, err = RS485FindDeviceOp(dev, op.MBMD.IEC61850)
}
return err
}