I use FreeRTOS for our ModBus TCP/RTU Bridge (STM32F107). The ModBus-TCP alone with the LWIP Stack is working fine. The same applies to the Modbus RTU alone. But when I use them together, the System hangs after a few seconds. I'm pretty sure this has something to do with my interrupt setting. But at the moment I have no idea what I'm doing wrong. I am glad for any help.

Thanks in advance.

Mathias Stucki

Which version of FreeRTOS are you using. If it is V7.6.0 or later then ensure configASSERT is defined as it will trap common interrupt priority misconfigurations, especially on STM32 parts.

Regards.

Thank your for the fast response. Now i have defined the configASSERT but it doesn't trap into the vAssertCalled function. Actually, the code stops at this position: (I have increased the Stack but without success)

# /* *** NOTE *********************************************************** If you find your application is crashing here then likely causes are: 1) Stack overflow - see http://www.freertos.org/Stacks-and-stack-overflow-checking.html 2) Incorrect interrupt priority assignment, especially on Cortex-M3 parts where numerically high priority values denote low actual interrupt priories, which can seem counter intuitive. See configMAXSYSCALLINTERRUPT_PRIORITY on http://www.freertos.org/a00110.html 3) Calling an API function from within a critical section or when the scheduler is suspended, or calling an API function that does not end in "FromISR" from an interrupt. 4) Using a queue or semaphore before it has been initialised or before the scheduler has been started (are interrupts firing before vTaskStartScheduler() has been called?). See http://www.freertos.org/FAQHelp.html for more tips. **********************************************************************/

	for( pxIterator = ( xListItem * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext ) /*lint !e826 !e740 The mini list structure is used as the list end to save RAM.  This is checked and valid. */
	{
		/* There is nothing to do here, we are just iterating to the
		wanted insertion position. */
	}