IOCAN

# Virtual Input

## Overview

A **Virtual Input** is a value you set **from the datalogger over USB**. The

datalogger presents a set of **sliders**; each Virtual Input is one slider you can

drag to set its value live. Use it to inject a value for **testing** and tuning —

exercising logic that consumes an input without the real sensor connected.

## Prerequisites

- The **datalogger** connected over **USB** to move the slider.

## Add it in the app

1. Add a new input and choose **Virtual Input** as the type.

2. Give it a clear **alias** (e.g. `Test Setpoint`).

3. That's it — the value is driven from the datalogger slider.

## Settings reference

This input has no type-specific settings — its value is set from the datalogger

slider over USB. See Common settings below.

## Common settings

Virtual Input also uses the shared setting — alias. See

[Common IO Settings](../Common-IO-Settings.md).

## Example — test setpoint

1. Type **Virtual Input**, alias `Test Setpoint`.

2. Reference `Test Setpoint` wherever you would normally use a measured input — for

   example as a term in a [Compare Input](Compare-Input.md) or

   [Math Divide Input](Math-Divide-Input.md).

3. In the datalogger, drag the `Test Setpoint` slider to different values to

   exercise the logic that consumes it.

## Troubleshooting

- **Value never changes:** the datalogger isn't connected over USB, or the slider

  hasn't been moved.

- **Other IO don't see it:** check they reference the correct **alias**.

## Related

- [Constant Value Input](Constant-Value-Input.md) — a fixed value that is not

  written at run time.

- [System Input](System-Input.md) — an internal value produced by the controller.