增加特性需求

api.go

@@ -28,6 +28,7 @@ type Client interface {
 	// ReadHoldingRegisters reads the contents of a contiguous block of
 	// holding registers in a remote device and returns register value.
 	ReadHoldingRegisters(address, quantity uint16) (results []byte, err error)
+	ReadCustomRegisters(command string) (results []byte, err error)
 	// WriteSingleRegister writes a single holding register in a remote
 	// device and returns register value.
 	WriteSingleRegister(address, value uint16) (results []byte, err error)
@@ -48,5 +49,6 @@ type Client interface {
 	ReadFIFOQueue(address uint16) (results []byte, err error)
 
 	Connect() (err error)
+	IsConnect() (err error)
 	Close() (err error)
 }

client.go

@@ -7,6 +7,7 @@ package modbus
 import (
 	"encoding/binary"
 	"fmt"
+	"k8s.io/klog/v2"
 )
 
 // ClientHandler is the interface that groups the Packager and Transporter methods.
@@ -123,6 +124,39 @@ func (mb *client) ReadHoldingRegisters(address, quantity uint16) (results []byte
 	return
 }
 
+func (mb *client) ReadCustomRegisters(command string) (results []byte, err error) {
+
+	request := ProtocolDataUnit{
+		Data:         dataBlock(1, 1),
+		CustomCode:   command,
+	}
+	aduRequest, err := mb.packager.Encode(&request)
+	if err != nil {
+		return
+	}
+	aduResponse, err := mb.transporter.Send(aduRequest)
+	if err != nil {
+		return
+	}
+	if err = mb.packager.Verify(aduRequest, aduResponse); err != nil {
+		return
+	}
+	response, err := mb.packager.Decode(aduResponse)
+	if err != nil {
+		return
+	}
+	if response.Data == nil || len(response.Data) == 0 {
+		// Empty response
+		err = fmt.Errorf("modbus: response data is empty")
+		return
+	}
+	if err != nil {
+		return
+	}
+	results = response.Data
+	return
+}
+
 // Request:
 //  Function code         : 1 byte (0x04)
 //  Starting address      : 2 bytes
@@ -435,6 +469,9 @@ func (mb *client) ReadFIFOQueue(address uint16) (results []byte, err error) {
 func (mb *client) Connect() (err error) {
 	return mb.transporter.Connect()
 }
+func (mb *client) IsConnect() (err error) {
+	return mb.transporter.IsConnect()
+}
 
 func (mb *client) Close() (err error) {
 	return mb.transporter.Close()
@@ -448,10 +485,12 @@ func (mb *client) send(request *ProtocolDataUnit) (response *ProtocolDataUnit, e
 	if err != nil {
 		return
 	}
+	klog.V(1).Info("Send request:", aduRequest)
 	aduResponse, err := mb.transporter.Send(aduRequest)
 	if err != nil {
 		return
 	}
+	klog.V(1).Info("Send response:", aduResponse)
 	if err = mb.packager.Verify(aduRequest, aduResponse); err != nil {
 		return
 	}