Moving Median in Ladder code

Do anyone have a simple way to calculate a "moving median" value? Or am I stuck maintaining a FIFO array, sorting that and then picking from the sorted array.

Can anyone suggest an efficient sort routine?

I work with DirectSoft4 and am starting in RSLogix5k (Ladder editing only).

( I am looking for a filter for spikes in analog data. We are also looking at greater signal conditioning, but we still seem to need a 'software' filter.)

This is the way I always do:


F10:0 = your analog input
F10:1 = averaged value

Use CPT instruction

F10:1 = (F10:0 + (F10:1 * 100)/101)

In this example you average on 100 scans.
Simple and easy

Ragrads

Antoine.