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自定义读取接口&自定义写入接口 #5

Merged
Fuyao merged 3 commits from cfy-feate-dev into main 2025-11-14 15:21:10 +08:00
Conversation 0 Commits 3 Files Changed 5 +60 -58
3 changed files with 60 additions and 58 deletions
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Showing only changes of commit d5e9ce78d9 - Show all commits

13
client.go
View File

@@ -1188,15 +1188,9 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
unitId: mc.unitId, unitId: mc.unitId,
} }
// if functionCode != fcCustomize { if functionCode != fcCustomize {
// err = ErrUnexpectedParameters
// mc.logger.Errorf("unexpected function code (%d)", functionCode)
// return
// }
if functionCode == 0 {
err = ErrUnexpectedParameters err = ErrUnexpectedParameters
mc.logger.Errorf("unexpected register type (%v)", functionCode) mc.logger.Errorf("unexpected function code (%d)", functionCode)
return return
} }
@@ -1208,7 +1202,8 @@ func (mc *ModbusClient) readRegistersWithFunctionCode(addr uint16, quantity uint
return return
} }
if quantity > 1024 { // 16 * 16 * 40
if quantity > 10240 {
err = ErrUnexpectedParameters err = ErrUnexpectedParameters
mc.logger.Error("quantity of registers exceeds 1024") mc.logger.Error("quantity of registers exceeds 1024")
return return

2
modbus.go
View File

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

103
rtu_transport.go
View File

@@ -8,7 +8,7 @@ import (
) )
const ( const (
maxRTUFrameLength int = 256 maxRTUFrameLength int = 256
) )
type rtuTransport struct { type rtuTransport struct {
@@ -21,10 +21,10 @@ type rtuTransport struct {
} }
type rtuLink interface { type rtuLink interface {
Close() (error) Close() error
Read([]byte) (int, error) Read([]byte) (int, error)
Write([]byte) (int, error) Write([]byte) (int, error)
SetDeadline(time.Time) (error) SetDeadline(time.Time) error
} }
// Returns a new RTU transport. // 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. // Runs a request across the rtu link and returns a response.
func (rt *rtuTransport) ExecuteRequest(req *pdu) (res *pdu, err error) { func (rt *rtuTransport) ExecuteRequest(req *pdu) (res *pdu, err error) {
var ts time.Time var ts time.Time
var t time.Duration var t time.Duration
var n int var n int
// set an i/o deadline on the link // 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 { if err != nil {
return 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 // build an RTU ADU out of the request object and
// send the final ADU+CRC on the wire // 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 { if err != nil {
return return
} }
@@ -112,7 +112,7 @@ func (rt *rtuTransport) ExecuteRequest(req *pdu) (res *pdu, err error) {
// Reads a request from the rtu link. // Reads a request from the rtu link.
func (rt *rtuTransport) ReadRequest() (req *pdu, err error) { func (rt *rtuTransport) ReadRequest() (req *pdu, err error) {
// reading requests from RTU links is currently unsupported // reading requests from RTU links is currently unsupported
err = fmt.Errorf("unimplemented") err = fmt.Errorf("unimplemented")
return return
} }
@@ -123,7 +123,7 @@ func (rt *rtuTransport) WriteResponse(res *pdu) (err error) {
// build an RTU ADU out of the request object and // build an RTU ADU out of the request object and
// send the final ADU+CRC on the wire // 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 { if err != nil {
return return
} }
@@ -135,16 +135,16 @@ func (rt *rtuTransport) WriteResponse(res *pdu) (err error) {
// Waits for, reads and decodes a frame from the rtu link. // Waits for, reads and decodes a frame from the rtu link.
func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) { func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {
var rxbuf []byte var rxbuf []byte
var byteCount int var byteCount int
var bytesNeeded int var bytesNeeded int
var crc crc 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 // read the serial ADU header: unit id (1 byte), function code (1 byte) and
// PDU length/exception code (1 byte) // 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 { if (byteCount > 0 || err == nil) && byteCount != 3 {
err = ErrShortFrame err = ErrShortFrame
return 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 // 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 // never read more than the max allowed frame length
if byteCount + bytesNeeded > maxRTUFrameLength { if byteCount+bytesNeeded > maxRTUFrameLength {
err = ErrProtocolError err = ErrProtocolError
return 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 { if err != nil && err != io.ErrUnexpectedEOF {
return return
} }
@@ -180,19 +180,19 @@ func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {
// compute the CRC on the entire frame, excluding the CRC // compute the CRC on the entire frame, excluding the CRC
crc.init() crc.init()
crc.add(rxbuf[0:3 + bytesNeeded - 2]) crc.add(rxbuf[0 : 3+bytesNeeded-2])
// compare CRC values // 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 err = ErrBadCRC
return return
} }
res = &pdu{ res = &pdu{
unitId: rxbuf[0], unitId: rxbuf[0],
functionCode: rxbuf[1], functionCode: rxbuf[1],
// pass the byte count + trailing data as payload, withtout the CRC // pass the byte count + trailing data as payload, withtout the CRC
payload: rxbuf[2:3 + bytesNeeded - 2], payload: rxbuf[2 : 3+bytesNeeded-2],
} }
return return
@@ -200,18 +200,18 @@ func (rt *rtuTransport) readRTUFrame() (res *pdu, err error) {
// Turns a PDU object into bytes. // Turns a PDU object into bytes.
func (rt *rtuTransport) assembleRTUFrame(p *pdu) (adu []byte) { func (rt *rtuTransport) assembleRTUFrame(p *pdu) (adu []byte) {
var crc crc var crc crc
adu = append(adu, p.unitId) adu = append(adu, p.unitId)
adu = append(adu, p.functionCode) adu = append(adu, p.functionCode)
adu = append(adu, p.payload...) adu = append(adu, p.payload...)
// run the ADU through the CRC generator // run the ADU through the CRC generator
crc.init() crc.init()
crc.add(adu) crc.add(adu)
// append the CRC to the ADU // append the CRC to the ADU
adu = append(adu, crc.value()...) adu = append(adu, crc.value()...)
return return
} }
@@ -220,24 +220,31 @@ func (rt *rtuTransport) assembleRTUFrame(p *pdu) (adu []byte) {
func expectedResponseLenth(responseCode uint8, responseLength uint8) (byteCount int, err error) { func expectedResponseLenth(responseCode uint8, responseLength uint8) (byteCount int, err error) {
switch responseCode { switch responseCode {
case fcReadHoldingRegisters, case fcReadHoldingRegisters,
fcReadInputRegisters, fcReadInputRegisters,
fcReadCoils, fcReadCoils,
fcReadDiscreteInputs: byteCount = int(responseLength) fcReadDiscreteInputs,
0x41:
byteCount = int(responseLength)
case fcWriteSingleRegister, case fcWriteSingleRegister,
fcWriteMultipleRegisters, fcWriteMultipleRegisters,
fcWriteSingleCoil, fcWriteSingleCoil,
fcWriteMultipleCoils: byteCount = 3 fcWriteMultipleCoils:
case fcMaskWriteRegister: byteCount = 5 byteCount = 3
case fcMaskWriteRegister:
byteCount = 5
case fcReadHoldingRegisters | 0x80, case fcReadHoldingRegisters | 0x80,
fcReadInputRegisters | 0x80, fcReadInputRegisters | 0x80,
fcReadCoils | 0x80, fcReadCoils | 0x80,
fcReadDiscreteInputs | 0x80, fcReadDiscreteInputs | 0x80,
fcWriteSingleRegister | 0x80, fcWriteSingleRegister | 0x80,
fcWriteMultipleRegisters | 0x80, fcWriteMultipleRegisters | 0x80,
fcWriteSingleCoil | 0x80, fcWriteSingleCoil | 0x80,
fcWriteMultipleCoils | 0x80, fcWriteMultipleCoils | 0x80,
fcMaskWriteRegister | 0x80: byteCount = 0 fcMaskWriteRegister | 0x80,
default: err = ErrProtocolError 0x41 | 0x80:
byteCount = 0
default:
err = ErrProtocolError
} }
return return