filter fast digital input

[otrotabi]

What it the easiest way to filter a fast digital input ? I am reading a turbine type flow meter on FDI1 and I would like to have a result that does not change permanently but is "averaged" every 10 seconds for example.

I think it is likely that there are some FB´s already developed for this use.

[Bastian_Schmitz · Accepted solution]

Hi,

Did you know OSCAT ? Based on this you could try one of the attached filter FBs.

The description of any of these Blocks is in the link above. 

[otrotabi]

Yes. I remember you told me some time ago you were willing to import OSCAT´s functions to TM172 format, I guess this is part of your effort. Thank you for sharing it.

I tried to compile a very simple example:

I got this error:

FILTER_MAV_DW(13) - error S1305: INC1 => Unknown function

So I downloaded it from a Siemens forum, is this code ok ?

IF X >= N - 1 THEN
  INC1 := 0;
ELSE
  INC1 := X + 1;
END_IF;

(* this elegant version is 50% slower
INC1 := X := (x + 1) MOD N;
*)

Is explicit dword to udint conversion as per my example needed or can I just :

They both compile fine.

[Bastian_Schmitz]

The complex point on OSCAT is that a lot of functions use internal other functions of the Library. In that case I double check not this point. Attached the full conversion till yet. ~10% is tested, Use of own risk

[otrotabi]

This is a Mastercard´s gift, it´s priceless 😊. Thank you.

If you would like me to help please do let me know. I will be happy to do it.

Regards