---
title: Rise and Fall
slug: litmusedge/rise-and-fall
docTags: 
createdAt: 2024-08-06T18:59:00.939Z
---

The Rise and Fall processor detects when a value crosses upward through a lower threshold or downward through an upper threshold, and reports the timestamp and duration of each crossing.

## Why use Rise and Fall

Use this processor to measure how long a value takes to transition past a threshold, for example, timing how long a tank takes to start filling once it drains below a low-level mark, or how long a motor takes to cool below an operating-temperature threshold.

## How it works

Set a **Lower** and an **Upper** threshold. When the current value crosses upward through **Lower**, the processor reports that as a rise, along with its timestamp and rise time, in seconds. When the current value crosses downward through **Upper**, the processor reports that as a fall, along with its timestamp and fall time, in seconds.

Use **Kpi** to choose whether the processor tracks rises, falls, or both. Use **Tolerance** to ignore fluctuations too small to count as a genuine rise or fall.

## Parameters

| **Parameter**      | **Details**                                                                                                     |
| ------------------ | --------------------------------------------------------------------------------------------------------------- |
| Kpi                | Whether to calculate rise, fall, or both, for the given data.                                                   |
| Upper              | The value above which the data is considered to be rising or falling.                                           |
| Lower              | The value below which the data is considered to be rising or falling.                                           |
| Tolerance          | Changes in the data below this amount are ignored when calculating rise and fall.                               |
| Pass Through Value | Determines whether the processor's output is the rise or fall event data or the original unchanged input value. |