IOCAN

# Constant Value Input

## Overview

A **Constant Value Input** simply outputs a single, fixed number. It has no

sensor — its value never changes on its own, but you can **tune it**

from the app. Use it as an adjustable constant or threshold that other IO can

reference by alias: a limit fed into a [Compare Input](Compare-Input.md), a fixed

operand for a [Math / Divide Input](Math-Divide-Input.md), or a calibration

offset used by a map.

## Prerequisites & hardware

None. This is a logical input with no source inputs — it

stands on its own. You only need somewhere to use it: another input, output or

map that will reference it by **alias**.

## Add it in the app

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

2. Give it a clear **alias** (e.g. `Shift Pressure Limit`).

3. Enter the **value**.

## Settings reference

> Schema: `config/ConstantValueConfiguration.proto`.

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

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

| **Value** | The fixed value this input reports | — (the value referencing IO expect) | sint32 | Can be negative. Change it any time to retune the constant; everything referencing this input picks up the new value. |

## Common settings

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

## Example — a tunable shift-pressure limit

1. Type **Constant Value Input**, alias `Shift Pressure Limit`.

2. Set **Value** to `850` (the limit in your pressure units).

3. In a [Compare Input](Compare-Input.md), compare your measured pressure against

   `Shift Pressure Limit`. To raise the limit later, edit this one value rather

   than every place it is used.

## Troubleshooting

- **The value never updates downstream:** confirm the other IO references this

  input by its **alias**, not a hard-coded number.

- **Wrong magnitude:** make sure the value is in the same units/scaling the

  consumer expects (e.g. if a map works in tenths, enter `850` for 85.0).

## Related

- [Compare Input](Compare-Input.md) — compare a signal against a value or constant.

- [Math / Divide Input](Math-Divide-Input.md) — combine inputs, often with a constant.