Timer Handling

The timer component provides an interface to function executions initiated by a timer.

Structure

  classDiagram
      CO_NODE o-- CO_TMR
      CO_TMR_ACTION o-- CO_TMR : APool, Acts
      CO_TMR_TIME o-- CO_TMR : TPool, Free, Use, Elapsed
      class CO_TMR {
        -uint32_t Max
        -uint32_t Freq
        +COTmrCreate(start, cycle, function, para) int16_t
        +COTmrDelete(action) int16_t
        +COTmrGetMinTime(unit) uint16_t
        +COTmrGetTicks(time, unit) int32_t
        +COTmrProcess()
        +COTmrService() int16_t
      }

Data

The class CO_TMR is defined within co_tmr.h and is responsible for the CANopen highspeed timer management. The following data members are in this class:

Data Member	Type	Description
Node	CO_NODE*	pointer to parent node object
Max	uint32_t	maximum nunber of timed actions
APool[]	CO_TMR_ACTION	timer action pool array
TPool[]	CO_TMR_TIME	timer event pool array
Acts	CO_TMR_ACTION*	pointer to the root of free actions linked list
Free	CO_TMR_TIME*	pointer to the root of free events linked list
Use	CO_TMR_TIME*	pointer to the root of used events linked list
Elapsed	CO_TMR_TIME*	pointer to the root of elapsed timers linked list
Freq	uint32_t	timer ticks per second

Note: The data within this structure must never be manipulated without the corresponding class member functions. This can lead to unpredictable behavior of the node.

Functions

The following table describes the API functions of the CANopen timer module. With the listed functions we can define the execution of actions after a given time interval with or without a cycle time. The functions are implemented within the source files: co_tmr.c/h.