IOCAN

# Mux Input

## Overview

A **Mux Input** (multiplexer) passes through **one of up to eight data inputs**,

chosen by a separate **selector** input — like a rotary selector switch. The

selector's value (0–7) decides which data input appears at the output. Use it to

switch between sources at runtime: different calibration sets, sensor banks, or

operating-mode values.

## Prerequisites & hardware

You need:

- A **selector input** whose value is `0`–`7` — any existing input, by alias.

  This is often a [Constant Value Input](Constant-Value-Input.md), an

  [Analog Switch Input](Analog-Switch-Input.md) or a mode value.

- One or more **data inputs** to choose between (up to eight), each by alias.

## Add it in the app

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

2. Choose the **selector** and **data inputs**.

3. Give it a clear **alias** (e.g. `Active Pressure Target`).

4. Assign the **selector input**, then fill **data input 0…7** with the sources

   you want to switch between.

## Settings reference

> Schema: `config/MuxInputConfigData.proto`.

| Setting | Meaning | Unit | Range / values | Notes |

|---|---|---|---|---|

| **Selector input** | Chooses which data input is passed through | — | an existing input (by alias), value `0`–`7` | Value `0` selects **Data input 0**, `1` selects **Data input 1**, … `7` selects **Data input 7**. |

| **Data inputs 0–7** | The eight candidate inputs to switch between | — | up to 8 existing inputs (by alias) | The output equals whichever one the selector points to. You need only fill the slots you use. |

**How it selects:** the output simply mirrors the data input whose slot number

matches the current **selector** value. A selector of `2` passes **Data input 2**

straight through.

## Common settings

Mux Input also uses the shared setting — alias. See [Common IO Settings](../Common-IO-Settings.md).

## Example — switch pressure target by drive mode

1. Type **Mux Input**, alias `Active Pressure Target`.

2. **Selector input** = your `Drive Mode` value (0 = Comfort, 1 = Sport).

3. **Data input 0** = `Comfort Pressure` constant.

4. **Data input 1** = `Sport Pressure` constant.

5. The output now follows the constant for whichever mode is selected.

## Troubleshooting

- **Output stuck on one source:** check the **selector** value actually changes

  and lands on `0`–`7`.

- **Unexpected / zero output:** a selected slot may be empty — fill **Data input

  N** for every selector value you use.

- **Selector out of range:** values above `7` have no matching slot; clamp or map

  the selector so it stays within `0`–`7`.

## Related

- [Constant Value Input](Constant-Value-Input.md) — fixed values to switch between.

- [Analog Switch Input](Analog-Switch-Input.md) — a multi-position selector source.

- [Map Input](Map-Input.md) — interpolate a value instead of selecting one.