> For the complete documentation index, see [llms.txt](https://docs.irs.systems/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.irs.systems/ltt/documentation/ltt-gui-manual/lttgui/dialogs/f3projectwizard/signalsdefinition.md).

# Signals Definition

{% hint style="info" %}
A **signal** is an analog output of your device under test or any other DUT related data you want to evaluate through a limit test (for example a CAN message).
{% endhint %}

![Signals](/files/Ga0fwcUTdpDNZlSAnRUZ)

To **add a signal** simply click on an empty row in the grid and type a name. Description is optional.

To **delete a signal** select a row and press the DEL key on your keyboard.

You assign a signal to one more **DUT types** (which you have defined previously). By default, each created signal is assigned to all available DUT Types. In most cases this common but it may happen, that one variant of your DUT has less/different analog outputs than another one.

Usually you want to evaluate all analog DUT outputs which are defined in the [MesSy configuration file](/ltt/documentation/ltt-gui-manual/configuration/messyconfiguration.md). Therefore you can import the signals defined there.

[go to initial setup guide](/ltt/documentation/ltt-gui-manual/gettingstarted/initial-setup-guide.md#SETUP_GUIDE)


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