# Data Dictionary

> A dashboard item that lists every signal name with its unit, data type, value range and the models that send it, flagging mixed units or types.

Source: https://proxus.io/docs/analyze/dashboard-items/data-dictionary

The **Data Dictionary**  item lists every signal name across the
assets as a data team designs against it: the unit and data type it is stored with, the lowest and highest value in
the window, and how many assets and which equipment models send it.

- **Flags.** A signal stored with more than one unit, or more than one data type, shows them in amber and comes first:
  the same name means different things on different machines.
- **Search.** Type part of a signal, unit, data type or model to narrow the list.
- **Summary.** How many signal names are shown and how many have mixed units or types.

Select a signal to filter the other items of the dashboard by it.

## Data fields

**Signal** is required: one row per asset and signal. **Unit** and **Data type** fill their columns, **Lowest value**
and **Highest value** the range (bind them with the **Min** and **Max** summaries), and **Equipment model** and
**Asset** the "used by" column.

## Where to see it

The Meridian demo plant uses it on **Meridian · Data Platform Command Center**.

## Related

- [Data Volume](https://proxus.io/docs/analyze/dashboard-items/data-volume)
- [Data History](https://proxus.io/docs/analyze/dashboard-items/data-history)
- [Proxus dashboard items](https://proxus.io/docs/analyze/dashboard-items)