====Assigning Types====

You can 'Tag' [[asset|assets]] in your ARDI system to give them //types// - one or more groups that they fit in to. For example, sensors can be grouped together by them all being tagged as 'Sensor'.

===Tag Hierarchy===

The tags themselves have their own [[hierarchy|hierarchy]] that take them from very general classifications (ie. 'Instrument') to very specific (ie. 'Yokogawa AXF Magnetic Flow Meter'). An example appears below.

{{tagtree.png?400}}

Thus if you tag something as a 'Yokogawa AXF', it is also //indirectly// tagged as 'Magnetic Flowmeter', 'Flowmeter' and 'Instrument' based on the tag hierarchy.

===Tags with Properties===

Apart from the ability to search through your system by classification, the type system has an additional benefit - **inheritance**.

By adding [[properties|properties]] to a //type//, you also add that same property to all assets that //use// that tag - either directly or indirectly.

So for example, you can create a type for a 'Air Temperature Sensor', adding the **Temperature  - Air** [[measurements|measurement]] and a **Calibration Date** recurring event property on it.

Any asset that uses the 'Air Temperature Sensor' type now will automatically include these properties. This makes it much easier to set up a system with recurring parts.

If you had a specific //model// of temperature sensor that you regularly use around the plant, you could even go a step further and make a sub-type of 'Air Temperature Sensor' for the model, then both the appearance of the item and add media (such as photographs, specification sheets and manuals) to your new type.

Then, when you tagged any asset as that model sensor, it would inherit the media from the //direct// type, plus the temperature measurement and calibration date properties from the //indirect// type.

===Suggested Types===

If you have a number of different types of media, and you're measuring the same property on more than one of them (ie. **water pressure** vs **air pressure**), then we suggest creating a different type //for each instrument and media type//.

This means that you'll have a structure similar to the following...

<WRAP round box>
**Sensor** > **Temperature Sensor** > **Water Temperature Sensor**

**Sensor** > **Temperature Sensor** > **Air Temperature Sensor**
</WRAP>

Although this is a little time-consuming during setup, it allows you to add new sensors to your ARDI system extremely quickly. For larger systems, it's a time-saving technique.

===Media===

As well as [[properties|properties]] and [[alerts|alerts]], [[media|media]] is also inherited.

Adding documentation - such as instruction manuals or work instructions - to a type distributes that media to all sub-objects. This makes administering your documents much easier - a single change to one asset feeds through to all of the sub-assets that share the type.

===License Issues===

Note that types do not count to your [[ardiadminguide:active_elements|active element]] count unless they have properties attached.