/**
* 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);
}
/* Create an interrupt handler for the transmit buffer empty interrupt
* (or an equivalent) for your target processor. This function should then
* call pxMBFrameCBTransmitterEmpty( ) which tells the protocol stack that
* a new character can be sent. The protocol stack will then call
* xMBPortSerialPutByte( ) to send the character.
*/
interrupt void prvvUARTTxReadyISR( void )
{
static unsigned int uiCnt = 0;
#if (TEST == TEST_TX)
if(uiCnt++ < 10)
xMBPortSerialPutByte('a');
else
vMBPortSerialEnable(false,false);
#elif (TEST == NO_TEST)
pxMBFrameCBTransmitterEmpty( );
#endif
PieCtrlRegs.PIEACK.all|=0x100; // Issue PIE ack
}
BOOL
xMBASCIITransmitFSM( void )
{
BOOL xNeedPoll = FALSE;
UCHAR ucByte;
assert( eRcvState == STATE_RX_IDLE );
switch ( eSndState )
{
/* Start of transmission. The start of a frame is defined by sending
* the character ':'. */
case STATE_TX_START:
ucByte = ':';
xMBPortSerialPutByte( ( CHAR )ucByte );
eSndState = STATE_TX_DATA;
eBytePos = BYTE_HIGH_NIBBLE;
break;
/* Send the data block. Each data byte is encoded as a character hex
* stream with the high nibble sent first and the low nibble sent
* last. If all data bytes are exhausted we send a '\r' character
* to end the transmission. */
case STATE_TX_DATA:
if( usSndBufferCount > 0 )
{
switch ( eBytePos )
{
case BYTE_HIGH_NIBBLE:
ucByte = prvucMBBIN2CHAR( ( UCHAR )( *pucSndBufferCur >> 4 ) );
xMBPortSerialPutByte( ( CHAR ) ucByte );
eBytePos = BYTE_LOW_NIBBLE;
break;
case BYTE_LOW_NIBBLE:
ucByte = prvucMBBIN2CHAR( ( UCHAR )( *pucSndBufferCur & 0x0F ) );
xMBPortSerialPutByte( ( CHAR )ucByte );
pucSndBufferCur++;
eBytePos = BYTE_HIGH_NIBBLE;
usSndBufferCount--;
break;
}
}
else
{
xMBPortSerialPutByte( MB_ASCII_DEFAULT_CR );
eSndState = STATE_TX_END;
}
break;
/* Finish the frame by sending a LF character. */
case STATE_TX_END:
xMBPortSerialPutByte( ( CHAR )ucMBLFCharacter );
/* We need another state to make sure that the CR character has
* been sent. */
eSndState = STATE_TX_NOTIFY;
break;
/* Notify the task which called eMBASCIISend that the frame has
* been sent. */
case STATE_TX_NOTIFY:
eSndState = STATE_TX_IDLE;
xNeedPoll = xMBPortEventPost( EV_FRAME_SENT );
/* Disable transmitter. This prevents another transmit buffer
* empty interrupt. */
vMBPortSerialEnable( TRUE, FALSE );
eSndState = STATE_TX_IDLE;
break;
/* We should not get a transmitter event if the transmitter is in
* idle state. */
case STATE_TX_IDLE:
/* enable receiver/disable transmitter. */
vMBPortSerialEnable( TRUE, FALSE );
break;
}
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
}
