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From: James Rogers <jimmaureenrogers@worldnet.att.net>
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Subject: Re: need ada timer routine
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Date: Tue, 04 Sep 2001 20:03:55 GMT
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Date: 2001-09-04T20:03:55+00:00
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Is your C routine a background process? If not you are likely to
encounter a gradual loop skew as the timer must wait for the called
function to complete.

If you want to reliably send data every 50 milliseconds you want
to use a task with a "delay until" statement in a loop.

The following example comes right out of the Ada Language Reference
Manual.

In your case the identifier "Period" would be defined as:

Period : constant Duration := 0.050;

declare
       use Ada.Calendar;
       Next_Time : Time := Clock + Period;
                          -- Period is a global constant of type
Duration
    begin
       loop               -- repeated every Period seconds
          delay until Next_Time;
          ... -- perform some actions
          Next_Time := Next_Time + Period;
       end loop;
    end;

Jim Rogers
Colorado Springs, Colorado USA

mop wrote:
> 
> i need a routine to pass serial data at a 20 hertz rate
> 
> For my Visual C I did "m_timer = SetTimer(1, 50, NULL);"  This now calls a
> built in API OnTimer(UINT nIDEvent) every 50 millisec.   Need something like
> this in Ada.