0x41

2025-11-13 22:28:48 +08:00
parent 0377201fc9
commit d5e9ce78d9
3 changed files with 60 additions and 58 deletions
--- a/client.go
+++ b/client.go
@@ -1188,15 +1188,9 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
 		unitId: mc.unitId,
 	}

-	// if functionCode != fcCustomize {
-	// 	err = ErrUnexpectedParameters
-	// 	mc.logger.Errorf("unexpected function code (%d)", functionCode)
-	// 	return
-	// }
-
-	if functionCode == 0 {
+	if functionCode != fcCustomize {
 		err = ErrUnexpectedParameters
-		mc.logger.Errorf("unexpected register type (%v)", functionCode)
+		mc.logger.Errorf("unexpected function code (%d)", functionCode)
 		return
 	}

@@ -1208,7 +1202,8 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
 		return
 	}

-	if quantity > 1024 {
+	// 16 * 16 * 40
+	if quantity > 10240 {
 		err = ErrUnexpectedParameters
 		mc.logger.Error("quantity of registers exceeds 1024")
 		return
--- a/modbus.go
+++ b/modbus.go
@@ -41,7 +41,7 @@ const (
 	fcWriteFileRecord uint8 = 0x15

 	// customize
-	fcCustomize uint8 = 0x29
+	fcCustomize uint8 = 0x41

 	// exception codes
 	exIllegalFunction         uint8 = 0x01
--- a/rtu_transport.go
+++ b/rtu_transport.go
@@ -8,7 +8,7 @@ import (
 )

 const (
-	maxRTUFrameLength	int = 256
+	maxRTUFrameLength int = 256
 )

 type rtuTransport struct {
@@ -21,10 +21,10 @@ type rtuTransport struct {
 }

 type rtuLink interface {
-	Close()		(error)
-	Read([]byte)	(int, error)
-	Write([]byte)	(int, error)
-	SetDeadline(time.Time)	(error)
+	Close() error
+	Read([]byte) (int, error)
+	Write([]byte) (int, error)
+	SetDeadline(time.Time) error
 }

 // Returns a new RTU transport.
@@ -58,11 +58,11 @@ func (rt *rtuTransport) Close() (err error) {
 // Runs a request across the rtu link and returns a response.
 func (rt *rtuTransport) ExecuteRequest(req *pdu) (res *pdu, err error) {
 	var ts time.Time
-	var t  time.Duration
-	var n  int
+	var t time.Duration
+	var n int

 	// set an i/o deadline on the link
-	err	= rt.link.SetDeadline(time.Now().Add(rt.timeout))
+	err = rt.link.SetDeadline(time.Now().Add(rt.timeout))
 	if err != nil {
 		return
 	}
@@ -78,7 +78,7 @@ func (rt *rtuTransport) ExecuteRequest(req *pdu) (res *pdu, err error) {

 	// build an RTU ADU out of the request object and
 	// send the final ADU+CRC on the wire
-	n, err	= rt.link.Write(rt.assembleRTUFrame(req))
+	n, err = rt.link.Write(rt.assembleRTUFrame(req))
 	if err != nil {
 		return
 	}
@@ -112,7 +112,7 @@ func (rt *rtuTransport) ExecuteRequest(req *pdu) (res *pdu, err error) {
 // Reads a request from the rtu link.
 func (rt *rtuTransport) ReadRequest() (req *pdu, err error) {
 	// reading requests from RTU links is currently unsupported
-	err	= fmt.Errorf("unimplemented")
+	err = fmt.Errorf("unimplemented")

 	return
 }
@@ -123,7 +123,7 @@ func (rt *rtuTransport) WriteResponse(res *pdu) (err error) {

 	// build an RTU ADU out of the request object and
 	// send the final ADU+CRC on the wire
-	n, err	= rt.link.Write(rt.assembleRTUFrame(res))
+	n, err = rt.link.Write(rt.assembleRTUFrame(res))
 	if err != nil {
 		return
 	}
@@ -135,16 +135,16 @@ func (rt *rtuTransport) WriteResponse(res *pdu) (err error) {

 // Waits for, reads and decodes a frame from the rtu link.
 func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {
-	var rxbuf	[]byte
-	var byteCount	int
-	var bytesNeeded	int
-	var crc		crc
+	var rxbuf []byte
+	var byteCount int
+	var bytesNeeded int
+	var crc crc

-	rxbuf		= make([]byte, maxRTUFrameLength)
+	rxbuf = make([]byte, 10243)

 	// read the serial ADU header: unit id (1 byte), function code (1 byte) and
 	// PDU length/exception code (1 byte)
-	byteCount, err	= io.ReadFull(rt.link, rxbuf[0:3])
+	byteCount, err = io.ReadFull(rt.link, rxbuf[0:3])
 	if (byteCount > 0 || err == nil) && byteCount != 3 {
 		err = ErrShortFrame
 		return
@@ -160,15 +160,15 @@ func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {
 	}

 	// we need to read 2 additional bytes of CRC after the payload
-	bytesNeeded	+= 2
+	bytesNeeded += 2

 	// never read more than the max allowed frame length
-	if byteCount + bytesNeeded > maxRTUFrameLength {
-		err	= ErrProtocolError
+	if byteCount+bytesNeeded > maxRTUFrameLength {
+		err = ErrProtocolError
 		return
 	}

-	byteCount, err	= io.ReadFull(rt.link, rxbuf[3:3 + bytesNeeded])
+	byteCount, err = io.ReadFull(rt.link, rxbuf[3:3+bytesNeeded])
 	if err != nil && err != io.ErrUnexpectedEOF {
 		return
 	}
@@ -180,19 +180,19 @@ func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {

 	// compute the CRC on the entire frame, excluding the CRC
 	crc.init()
-	crc.add(rxbuf[0:3 + bytesNeeded - 2])
+	crc.add(rxbuf[0 : 3+bytesNeeded-2])

 	// compare CRC values
-	if !crc.isEqual(rxbuf[3 + bytesNeeded - 2], rxbuf[3 + bytesNeeded - 1]) {
+	if !crc.isEqual(rxbuf[3+bytesNeeded-2], rxbuf[3+bytesNeeded-1]) {
 		err = ErrBadCRC
 		return
 	}

-	res	= &pdu{
-		unitId:		rxbuf[0],
-		functionCode:	rxbuf[1],
+	res = &pdu{
+		unitId:       rxbuf[0],
+		functionCode: rxbuf[1],
 		// pass the byte count + trailing data as payload, withtout the CRC
-		payload:	rxbuf[2:3 + bytesNeeded  - 2],
+		payload: rxbuf[2 : 3+bytesNeeded-2],
 	}

 	return
@@ -200,18 +200,18 @@ func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {

 // Turns a PDU object into bytes.
 func (rt *rtuTransport) assembleRTUFrame(p *pdu) (adu []byte) {
-	var crc		crc
+	var crc crc

-	adu	= append(adu, p.unitId)
-	adu	= append(adu, p.functionCode)
-	adu	= append(adu, p.payload...)
+	adu = append(adu, p.unitId)
+	adu = append(adu, p.functionCode)
+	adu = append(adu, p.payload...)

 	// run the ADU through the CRC generator
 	crc.init()
 	crc.add(adu)

 	// append the CRC to the ADU
-	adu	= append(adu, crc.value()...)
+	adu = append(adu, crc.value()...)

 	return
 }
@@ -220,24 +220,31 @@ func (rt *rtuTransport) assembleRTUFrame(p *pdu) (adu []byte) {
 func expectedResponseLenth(responseCode uint8, responseLength uint8) (byteCount int, err error) {
 	switch responseCode {
 	case fcReadHoldingRegisters,
-	     fcReadInputRegisters,
-	     fcReadCoils,
-	     fcReadDiscreteInputs:            byteCount = int(responseLength)
+		fcReadInputRegisters,
+		fcReadCoils,
+		fcReadDiscreteInputs,
+		0x41:
+		byteCount = int(responseLength)
 	case fcWriteSingleRegister,
-	     fcWriteMultipleRegisters,
-	     fcWriteSingleCoil,
-	     fcWriteMultipleCoils:            byteCount = 3
-	case fcMaskWriteRegister:             byteCount = 5
+		fcWriteMultipleRegisters,
+		fcWriteSingleCoil,
+		fcWriteMultipleCoils:
+		byteCount = 3
+	case fcMaskWriteRegister:
+		byteCount = 5
 	case fcReadHoldingRegisters | 0x80,
-	     fcReadInputRegisters | 0x80,
-	     fcReadCoils | 0x80,
-	     fcReadDiscreteInputs | 0x80,
-	     fcWriteSingleRegister | 0x80,
-	     fcWriteMultipleRegisters | 0x80,
-	     fcWriteSingleCoil | 0x80,
-	     fcWriteMultipleCoils | 0x80,
-	     fcMaskWriteRegister | 0x80:      byteCount = 0
-	default: err = ErrProtocolError
+		fcReadInputRegisters | 0x80,
+		fcReadCoils | 0x80,
+		fcReadDiscreteInputs | 0x80,
+		fcWriteSingleRegister | 0x80,
+		fcWriteMultipleRegisters | 0x80,
+		fcWriteSingleCoil | 0x80,
+		fcWriteMultipleCoils | 0x80,
+		fcMaskWriteRegister | 0x80,
+		0x41 | 0x80:
+		byteCount = 0
+	default:
+		err = ErrProtocolError
 	}

 	return