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

Reviewed-on: #10

rtu_transport.go

@@ -465,7 +465,8 @@ func (rt *rtuTransport) readRTUFrameWithRes() (res *pdu, err error) {
 	// 标准modbus响应已读取完成，现在读取自定义数据
 	// 设置5秒超时来读取自定义数据
 	customDataTimeout := 5 * time.Second
-	err = rt.link.SetDeadline(time.Now().Add(customDataTimeout))
+	deadline := time.Now().Add(customDataTimeout)
+	err = rt.link.SetDeadline(deadline)
 	if err != nil {
 		return
 	}
@@ -477,6 +478,16 @@ func (rt *rtuTransport) readRTUFrameWithRes() (res *pdu, err error) {
 	var lastErr error // 记录最后一次非超时错误
 
 	for {
+		// 检查是否已经超时
+		if time.Now().After(deadline) {
+			// 超时时间到，退出循环
+			// 如果有之前记录的错误，使用它；否则err保持为nil（超时是正常的）
+			if lastErr != nil {
+				err = lastErr
+			}
+			break
+		}
+
 		// 检查缓冲区是否还有空间
 		if startPos+totalRead+len(tempBuf) > len(rxbuf) {
 			// 如果缓冲区不够，扩展它
@@ -497,7 +508,7 @@ func (rt *rtuTransport) readRTUFrameWithRes() (res *pdu, err error) {
 		if readErr != nil {
 			if os.IsTimeout(readErr) {
 				// 超时时间到，退出循环
-				// 如果有之前记录的错误，使用它；否则使用超时错误
+				// 如果有之前记录的错误，使用它；否则err保持为nil（超时是正常的）
 				if lastErr != nil {
 					err = lastErr
 				}

serial.go

@@ -35,9 +35,12 @@ func (spw *serialPortWrapper) Open() (err error) {
 	var parity string
 
 	switch spw.conf.Parity {
-	case PARITY_NONE:	parity	= "N"
+	case PARITY_NONE:
-	case PARITY_EVEN:	parity	= "E"
+		parity = "N"
-	case PARITY_ODD:	parity	= "O"
+	case PARITY_EVEN:
+		parity = "E"
+	case PARITY_ODD:
+		parity = "O"
 	}
 
 	spw.port, err = serial.Open(&serial.Config{
@@ -46,7 +49,7 @@ func (spw *serialPortWrapper) Open() (err error) {
 		DataBits: int(spw.conf.DataBits),
 		Parity:   parity,
 		StopBits: int(spw.conf.StopBits),
-		Timeout:	10 * time.Millisecond,
+		Timeout:  100 * time.Millisecond,
 	})
 
 	return
@@ -69,6 +72,7 @@ func (spw *serialPortWrapper) Close() (err error) {
 //   - the serial port's receive buffer is empty: port.Read() blocks for
 //     up to 10ms and returns serial.ErrTimeout. The serial timeout error is
 //     masked and Read() returns with no data.
+//
 // As the higher-level methods use io.ReadFull(), Read() will be called
 // as many times as necessary until either enough bytes have been read or an
 // error is returned (ErrRequestTimedOut or any other i/o error).