ADL distance traveled pulse

[Martin]

Ive got a GPS connected to an ADL and I managed to get the speed reading over RS232

Im also integrating the Speed channel but would like to reset it after every 10m so that I can generate a pulse from that to trigger an ODO


Is there a way to reset this maths channel in the ADL?

Or another way to trigger every 10m?


Thanks

[DarrenR]

Hi Martin,
You can use a 3D table to do the maths where the X axis is also the result of the table and the distance. The Y axis is speed. You can calculate your distance to the mm and table values > 10m = the value minus 10m so it rolls over but doesn't lose the distance travelled past 10m.
Then make a 2D table that is 1 when over 5m and 0 when under 5 meters and set the result the an output as on/off.

I've been through this before on here i'm sure, with a more detailed explanation.

[Martin]

Okay, Ill have a look, thanks Darren.


Is the calculation rate of the device not crucial to this calculation of distance?

I suspect the ADL is different to the SDL

[DarrenR]

Yes the calculation rate is very crucial, but only if it is too slow.
The table calc rate is 50Hz (pretty sure even on the old ADL) so at 300kmh you travel 1.666m in 20mS, meaning you could get a pulse every 3.5m up to 300kmh.

You need to factor the 50Hz calc rate into the table values so you add the distance you travel in 20mS for the speed you are travelling.