void
eMBRTUStart( void )
{
ENTER_CRITICAL_SECTION( );
/* Initially the receiver is in the state STATE_RX_INIT. we start
* the timer and if no character is received within t3.5 we change
* to STATE_RX_IDLE. This makes sure that we delay startup of the
* modbus protocol stack until the bus is free.
*/
eRcvState = STATE_RX_INIT;
vMBPortSerialEnable( TRUE, FALSE );
vMBPortTimersEnable( );
EXIT_CRITICAL_SECTION( );
}
/**
* Start ModBus master
*/
void eMBRTUStart(void)
{
DEBUG_PUTSTRING("MODBUS Start");
ENTER_CRITICAL_SECTION( );
/* Initially the receiver is in the state STATE_RX_INIT. we start
* the timer and if no character is received within t3.5 we change
* to STATE_RX_IDLE. This makes sure that we delay startup of the
* modbus protocol stack until the bus is free.
*/
eRcvState = STATE_RX_INIT;
vMBPortSerialEnable( TRUE, FALSE );
vMBPortTimersEnable( );
EXIT_CRITICAL_SECTION( );
/* Give the target an initial kick */
xMBPortSerialPutByte(0);
xMBPortSerialPutByte(0);
xMBPortSerialPutByte(0);
xMBPortSerialPutByte(0);
sleep(2);
}
BOOL
xMBASCIIReceiveFSM( void )
{
BOOL xNeedPoll = FALSE;
UCHAR ucByte;
UCHAR ucResult;
assert( eSndState == STATE_TX_IDLE );
( void )xMBPortSerialGetByte( ( CHAR * ) & ucByte );
switch ( eRcvState )
{
/* A new character is received. If the character is a ':' the input
* buffer is cleared. A CR-character signals the end of the data
* block. Other characters are part of the data block and their
* ASCII value is converted back to a binary representation.
*/
case STATE_RX_RCV:
/* Enable timer for character timeout. */
vMBPortTimersEnable( );
if( ucByte == ':' )
{
/* Empty receive buffer. */
eBytePos = BYTE_HIGH_NIBBLE;
usRcvBufferPos = 0;
}
else if( ucByte == MB_ASCII_DEFAULT_CR )
{
eRcvState = STATE_RX_WAIT_EOF;
}
else
{
ucResult = prvucMBCHAR2BIN( ucByte );
switch ( eBytePos )
{
/* High nibble of the byte comes first. We check for
* a buffer overflow here. */
case BYTE_HIGH_NIBBLE:
if( usRcvBufferPos < MB_SER_PDU_SIZE_MAX )
{
ucASCIIBuf[usRcvBufferPos] = ( UCHAR )( ucResult << 4 );
eBytePos = BYTE_LOW_NIBBLE;
break;
}
else
{
/* not handled in Modbus specification but seems
* a resonable implementation. */
eRcvState = STATE_RX_IDLE;
/* Disable previously activated timer because of error state. */
vMBPortTimersDisable( );
}
break;
case BYTE_LOW_NIBBLE:
ucASCIIBuf[usRcvBufferPos] |= ucResult;
usRcvBufferPos++;
eBytePos = BYTE_HIGH_NIBBLE;
break;
}
}
break;
case STATE_RX_WAIT_EOF:
if( ucByte == ucMBLFCharacter )
{
/* Disable character timeout timer because all characters are
* received. */
vMBPortTimersDisable( );
/* Receiver is again in idle state. */
eRcvState = STATE_RX_IDLE;
/* Notify the caller of eMBASCIIReceive that a new frame
* was received. */
xNeedPoll = xMBPortEventPost( EV_FRAME_RECEIVED );
}
else if( ucByte == ':' )
{
/* Empty receive buffer and back to receive state. */
eBytePos = BYTE_HIGH_NIBBLE;
usRcvBufferPos = 0;
eRcvState = STATE_RX_RCV;
/* Enable timer for character timeout. */
vMBPortTimersEnable( );
}
else
{
/* Frame is not okay. Delete entire frame. */
eRcvState = STATE_RX_IDLE;
}
break;
case STATE_RX_IDLE:
if( ucByte == ':' )
{
/* Enable timer for character timeout. */
vMBPortTimersEnable( );
/* Reset the input buffers to store the frame. */
usRcvBufferPos = 0;;
eBytePos = BYTE_HIGH_NIBBLE;
eRcvState = STATE_RX_RCV;
}
break;
}
return xNeedPoll;
}
void
main( void )
{
eMBErrorCode eStatus;
/* Use external 32.768 Hz crystal to generate 4.194.304 Hz bus clock */
ICGC1 = 0x38; // ??=0,RANGE=0,REFS=1,CLKS=1:1,OSCSTEN=0,??=0:0
while( ICGS2_DCOS == 0 );
#if 0
/* Test code for porting
*/
#if 1
/* Timer test
* Comment out call to pxMBPortCBTimerExpired() in prvvTIMERExpiredISR when testing the timer
*/
/* Disable the COP watchdog */
SOPT = 0x53; // COPE=0,COPT=1,STOPE=0,??=1:0:0,BKGDPE=1,??=1
( void )xMBPortTimersInit( 20000 );
EnableInterrupts;
for( ;; )
{
vMBPortTimersEnable( );
_Wait; // wait for an interrupt
/* toggle LED1 */
PTFD_PTFD0 = !PTFD_PTFD0;
PTFDD_PTFDD0 = 1;
}
#else
/* Receiver test
* Comment out call to pxMBFrameCBByteReceived() in prvvUARTRxISR() when testing the receiver
*/
/* Disable the COP watchdog */
SOPT = 0x53; // COPE=0,COPT=1,STOPE=0,??=1:0:0,BKGDPE=1,??=1
/* Enable the receiver. */
assert( xMBPortSerialInit( 0, 9600, 8, MB_PAR_NONE ) );
EnableInterrupts;
for( ;; )
{
UCHAR ucByte;
vMBPortSerialEnable( TRUE, FALSE );
_Wait; // wait for an interrupt
assert( xMBPortSerialGetByte( &ucByte ) );
/* toggle LED1 */
PTFD_PTFD0 = !PTFD_PTFD0;
PTFDD_PTFDD0 = 1;
/* Transmitter test
* Comment out call to pxMBFrameCBTransmitterEmpty() in prvvUARTTxReadyISR() when testing the transmitter
*/
#if 0
vMBPortSerialEnable( FALSE, TRUE );
assert( xMBPortSerialPutByte( ucByte ) );
_Wait; // wait for an interrupt
/* toggle LED1 */
PTFD_PTFD0 = !PTFD_PTFD0;
#endif // Transmitter test
}
#endif // Receiver test
#else
/* Demo
* NOTE: Make sure the callbacks in the three ISPs have been restored after above testing
*/
/* Initialization */
eStatus = eMBInit( MB_RTU, 0x0A, 0, 38400, MB_PAR_EVEN );
// eStatus = eMBInit( MB_ASCII, 0x0A, 0, 38400, MB_PAR_EVEN );
/* Enable the Modbus Protocol Stack. */
eStatus = eMBEnable( );
/* Start polling */
EnableInterrupts;
for( ;; )
{
/* Poll for Modbus events */
( void )eMBPoll( );
/* Count the number of polls */
usRegInputBuf[0]++;
/* Count the number of timer overflows */
if( TPM1SC_TOF )
{
TPM1SC_TOF = 0;
ENTER_CRITICAL_SECTION( );
if( ++usRegInputBuf[1] == 0 ) // Happens every 2 seconds
usRegInputBuf[2]++; // Happens every 36.4 hours
EXIT_CRITICAL_SECTION( );
}
/* Keep the COP watchdog happy */
__RESET_WATCHDOG( );
}
#endif // Test code when porting
}
