Send timeout is set to 10 ms. Without timeout PLC can be blocked by CAN driver: if CAN bus is not connected to controller CAN driver never returns and therfore PLC application halts. This is a temporary solution.
// ----------------------------------------------------------------------------
// ATMEL Microcontroller Software Support - ROUSSET -
// ----------------------------------------------------------------------------
// DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
// DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
// OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ----------------------------------------------------------------------------
// File Name : interrupt_timer.c
// Object : Timer interrupt management
// : Use AT91B_LED7 & AT91B_LED8 for status interrupt
// Creation : JPP 08-Sep-2005
// ----------------------------------------------------------------------------
// Include Standard LIB files
#include "config.h"
//* Global variable
int timer0_interrupt = 0;
#define TIMER0_INTERRUPT_LEVEL 1
/*-----------------*/
/* Clock Selection */
/*-----------------*/
#define TC_CLKS 0x7
#define TC_CLKS_MCK2 0x0
#define TC_CLKS_MCK8 0x1
#define TC_CLKS_MCK32 0x2
#define TC_CLKS_MCK128 0x3
#define TC_CLKS_MCK1024 0x4
//*------------------------- Internal Function --------------------------------
//*----------------------------------------------------------------------------
//* Function Name : AT91F_TC_Open
//* Object : Initialize Timer Counter Channel and enable is clock
//* Input Parameters : <tc_pt> = TC Channel Descriptor Pointer
//* <mode> = Timer Counter Mode
//* : <TimerId> = Timer peripheral ID definitions
//* Output Parameters : None
//*----------------------------------------------------------------------------
void AT91F_TC_Open ( AT91PS_TC TC_pt, unsigned int Mode, unsigned int TimerId)
{
unsigned int dummy;
//* First, enable the clock of the TIMER
AT91F_PMC_EnablePeriphClock ( AT91C_BASE_PMC, 1<< TimerId ) ;
//* Disable the clock and the interrupts
TC_pt->TC_CCR = AT91C_TC_CLKDIS ;
TC_pt->TC_IDR = 0xFFFFFFFF ;
//* Clear status bit
dummy = TC_pt->TC_SR;
//* Suppress warning variable "dummy" was set but never used
dummy = dummy;
//* Set the Mode of the Timer Counter
TC_pt->TC_CMR = Mode ;
//* Enable the clock
TC_pt->TC_CCR = AT91C_TC_CLKEN ;
}
//*------------------------- Interrupt Function -------------------------------
//*----------------------------------------------------------------------------
//* Function Name : timer0_c_irq_handler
//* Object : C handler interrupt function calAT91B_LED by the interrupts
//* assembling routine
//* Output Parameters : increment count_timer0_interrupt
//*----------------------------------------------------------------------------
void timer0_c_irq_handler(void)
{
AT91PS_TC TC_pt = AT91C_BASE_TC0;
unsigned int dummy;
//* AcknowAT91B_LEDge interrupt status
dummy = TC_pt->TC_SR;
//* Suppress warning variable "dummy" was set but never used
dummy = dummy;
timer0_interrupt = TRUE;
}
//*-------------------------- External Function -------------------------------
//*----------------------------------------------------------------------------
//* Function Name : timer_init
//* Object : Init timer counter
//* Input Parameters : none
//* Output Parameters : TRUE
//*----------------------------------------------------------------------------
void timer_init (unsigned int time)
{
//* Open timer0
AT91F_TC_Open(AT91C_BASE_TC0,TC_CLKS_MCK8 | AT91C_TC_WAVESEL_UP_AUTO,AT91C_ID_TC0);
//* Open Timer 0 interrupt
AT91F_AIC_ConfigureIt ( AT91C_BASE_AIC, AT91C_ID_TC0, TIMER0_INTERRUPT_LEVEL,AT91C_AIC_SRCTYPE_INT_HIGH_LEVEL, timer0_c_irq_handler);
AT91C_BASE_TC0->TC_IER = AT91C_TC_CPCS; // IRQ enable CPC
AT91F_AIC_EnableIt (AT91C_BASE_AIC, AT91C_ID_TC0);
AT91C_BASE_TC0->TC_RC = (unsigned int)(AT91C_MASTER_CLOCK / 8 * time / 1000);
//* Start timer0
AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG ;
}