Merge branch 'main' of https://git.whblueocean.cn/communication-protocol/modbus into cfy-feat-dev

Reviewed-on: #4

client.go

@@ -773,6 +773,62 @@ func (mc *ModbusClient) WriteRegister(addr uint16, value uint16) (err error) {
 	return
 }
 
+// Writes a single 16-bit register (function code 06).
+func (mc *ModbusClient) WriteRegisterWithRes(addr uint16, value uint16) (bytes []byte, err error) {
+	var req *pdu
+	var res *pdu
+
+	mc.lock.Lock()
+	defer mc.lock.Unlock()
+
+	// create and fill in the request object
+	req = &pdu{
+		unitId:       mc.unitId,
+		functionCode: fcWriteSingleRegister,
+	}
+
+	// register address
+	req.payload = uint16ToBytes(BIG_ENDIAN, addr)
+	// register value
+	req.payload = append(req.payload, uint16ToBytes(mc.endianness, value)...)
+
+	// run the request across the transport and wait for a response
+	res, err = mc.executeRequest(req)
+	if err != nil {
+		return
+	}
+
+	// validate the response code
+	switch {
+	case res.functionCode == req.functionCode:
+		// expect 4 bytes (2 byte of address + 2 bytes of value)
+		if len(res.payload) != 4 ||
+			// bytes 1-2 should be the register address
+			bytesToUint16(BIG_ENDIAN, res.payload[0:2]) != addr ||
+			// bytes 3-4 should be the value
+			bytesToUint16(mc.endianness, res.payload[2:4]) != value {
+			err = ErrProtocolError
+			return
+		}
+
+		bytes = req.payload[1:]
+
+	case res.functionCode == (req.functionCode | 0x80):
+		if len(res.payload) != 1 {
+			err = ErrProtocolError
+			return
+		}
+
+		err = mapExceptionCodeToError(res.payload[0])
+
+	default:
+		err = ErrProtocolError
+		mc.logger.Warningf("unexpected response code (%v)", res.functionCode)
+	}
+
+	return
+}
+
 // Writes multiple 16-bit registers (function code 16).
 func (mc *ModbusClient) WriteRegisters(addr uint16, values []uint16) (err error) {
 	var payload []byte
@@ -1138,12 +1194,6 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
 		return
 	}
 
-	if functionCode == 0 {
-		err = ErrUnexpectedParameters
-		mc.logger.Errorf("unexpected register type (%v)", functionCode)
-		return
-	}
-
 	req.functionCode = functionCode
 
 	if quantity == 0 {
@@ -1152,7 +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
@@ -1176,21 +1227,53 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
 	}
 
 	// validate the response code
+	// switch {
+	// case res.functionCode == req.functionCode:
+	// 	// make sure the payload length is what we expect
+	// 	// (1 byte of length + 2 bytes per register)
+	// 	if len(res.payload) != 1+2*int(quantity) {
+	// 		err = ErrProtocolError
+	// 		return
+	// 	}
+
+	// 	// validate the byte count field
+	// 	// (2 bytes per register * number of registers)
+	// 	if uint(res.payload[0]) != 2*uint(quantity) {
+	// 		err = ErrProtocolError
+	// 		return
+	// 	}
+
+	// 	// remove the byte count field from the returned slice
+	// 	bytes = res.payload[1:]
+
+	// case res.functionCode == (req.functionCode | 0x80):
+	// 	if len(res.payload) != 1 {
+	// 		err = ErrProtocolError
+	// 		return
+	// 	}
+
+	// 	err = mapExceptionCodeToError(res.payload[0])
+
+	// default:
+	// 	err = ErrProtocolError
+	// 	mc.logger.Warningf("unexpected response code (%v)", res.functionCode)
+	// }
+
 	switch {
 	case res.functionCode == req.functionCode:
 		// make sure the payload length is what we expect
 		// (1 byte of length + 2 bytes per register)
-		if len(res.payload) != 1+2*int(quantity) {
-			err = ErrProtocolError
-			return
-		}
+		// if len(res.payload) != 1+2*int(quantity) {
+		// 	err = ErrProtocolError
+		// 	return
+		// }
 
 		// validate the byte count field
 		// (2 bytes per register * number of registers)
-		if uint(res.payload[0]) != 2*uint(quantity) {
-			err = ErrProtocolError
-			return
-		}
+		// if uint(res.payload[0]) != 2*uint(quantity) {
+		// 	err = ErrProtocolError
+		// 	return
+		// }
 
 		// remove the byte count field from the returned slice
 		bytes = res.payload[1:]

modbus.go

@@ -41,7 +41,7 @@ const (
 	fcWriteFileRecord uint8 = 0x15
 
 	// customize
-	fcCustomize uint8 = 0x29
+	fcCustomize uint8 = 0x41
 
 	// exception codes
 	exIllegalFunction         uint8 = 0x01

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