add modbus.Client initialization

Signed-off-by: SammyOina <[email protected]>

modbus/modbus.go

@@ -0,0 +1,114 @@
+package modbus
+
+import (
+	"log"
+	"reflect"
+	"time"
+
+	"github.com/goburrow/modbus"
+	"github.com/goburrow/serial"
+)
+
+// TCPHandlerOptions defines optional handler values.
+type TCPHandlerOptions struct {
+	IdleTimeout time.Duration
+	Logger      *log.Logger
+	SlaveId     byte
+	Timeout     time.Duration
+}
+
+// NewRTUClient initializes a new modbus.Client on TCP protocol from the address
+// and handler options provided.
+func NewTCPClient(address string, config TCPHandlerOptions) (modbus.Client, error) {
+	handler := modbus.NewTCPClientHandler(address)
+	if err := handler.Connect(); err != nil {
+		return nil, err
+	}
+	if !isZeroValue(config.IdleTimeout) {
+		handler.IdleTimeout = config.IdleTimeout
+	}
+	if !isZeroValue(config.Logger) {
+		handler.Logger = config.Logger
+	}
+	if !isZeroValue(config.SlaveId) {
+		handler.SlaveId = config.SlaveId
+	}
+	if !isZeroValue(config.Timeout) {
+		handler.Timeout = config.Timeout
+	}
+	return modbus.NewClient(handler), nil
+}
+
+// RTUHandlerOptions defines optional handler values.
+type RTUHandlerOptions struct {
+	BaudRate    int
+	Config      serial.Config
+	DataBits    int
+	IdleTimeout time.Duration
+	Logger      *log.Logger
+	Parity      string
+	RS485       serial.RS485Config
+	SlaveId     byte
+	StopBits    int
+	Timeout     time.Duration
+}
+
+// NewRTUClient initializes a new modbus.Client on RTU/ASCII protocol from the address
+// and handler options provided.
+func NewRTUClient(address string, config RTUHandlerOptions) (modbus.Client, error) {
+	handler := modbus.NewRTUClientHandler(address)
+	if err := handler.Connect(); err != nil {
+		return nil, err
+	}
+	if !isZeroValue(config.BaudRate) {
+		handler.BaudRate = config.BaudRate
+	}
+	if !isZeroValue(config.Config) {
+		handler.Config = config.Config
+	}
+	if !isZeroValue(config.DataBits) {
+		handler.DataBits = config.DataBits
+	}
+	if !isZeroValue(config.IdleTimeout) {
+		handler.IdleTimeout = config.IdleTimeout
+	}
+	if !isZeroValue(config.Logger) {
+		handler.Logger = config.Logger
+	}
+	if !isZeroValue(config.Parity) {
+		handler.Parity = config.Parity
+	}
+	if !isZeroValue(config.RS485) {
+		handler.RS485 = config.RS485
+	}
+	if !isZeroValue(config.SlaveId) {
+		handler.SlaveId = config.SlaveId
+	}
+	if !isZeroValue(config.StopBits) {
+		handler.StopBits = config.StopBits
+	}
+	if !isZeroValue(config.Timeout) {
+		handler.Timeout = config.Timeout
+	}
+	return modbus.NewClient(handler), nil
+}
+
+func isZeroValue(val interface{}) bool {
+	v := reflect.ValueOf(val)
+	switch v.Kind() {
+	case reflect.Func, reflect.Map, reflect.Slice:
+		return v.IsNil()
+	case reflect.Bool:
+		return !v.Bool()
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return v.Int() == 0
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		return v.Uint() == 0
+	case reflect.Float32, reflect.Float64:
+		return v.Float() == 0
+	case reflect.Interface, reflect.Ptr:
+		return v.IsNil()
+	default:
+		return reflect.DeepEqual(v.Interface(), reflect.Zero(v.Type()).Interface())
+	}
+}