Problem in measuring time!!

Hannes Mayer h.mayer at
Mon Oct 11 18:26:57 CEST 2004

Tarik KHOUTAIF wrote:
> Hi Hannes, Hi Philipe
> That pleased to me to receive your answers. 
> The rt_get_cpu_time_ns() returns time CPU, on the other hand the rt_get_time_ns() returns time in tick clock. 
> I work in the periodic mode and not oneshot mode (When I use the one shot mode the value of lacapture of time is null).I my application I use 3 modules, module_init_port in which I initialize the serial port and the timer (rt_start_timer(1E1)), in the module module_send_and_wait "Master" I makes rt_get_time_ns() after writing and after reading in the serial port.  In the module module_wait_and_answer I make rt_get_time_ns() after reading and after writing in the serial port . 
> Is what the fact of initializing the timer in another module other than this in which we does rt_get_time_ns(), does not pose problem? 
> Is the function get_timeof_day() returns the real time value of time? 
> Best regards,
> Tarik


I've not dealt with that functions in detail, but I think rt_get_cpu_time_ns()
works in any case, since it returns the CPU time independent of any rtai timer.

Best regards,

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