Index manager allows you to control *Layer variables* such as *Assets*, *Mappings* and *Devices* with DMX.
Index manager is categorized into *collections* and *slots*.
If you set the DMX flag of a layer variable of one of these 3 types to true and set it to 16bit, then you'll be able to use it with **Index manager**.
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**Good to know:** all stock layer templates have all variables set up to work with Index manager out of the box.
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When you assign a particular layer to DMX In window, you'll see which channel these variables will listen to. In the above example *Video asset* variable of the *Video* layer will be determined by channel 16 and 17. In the above image, both of these channels are 0.
This means that this Video asset variable will be set to the video asset in collection 0 and slot 0.
## Filling the slots
You can fill the slots automatically or manually.
### Autofilling Index Manager
To fill the slots automatically, you can click on the properties icon and select Autofill.
Autofill analyses the names of objects (assets, mappings or devices) and asset collections and assigns them to the corresponding collection and slot.
For example, the video asset *005\_theSnacks.mp4* is assigned to collection 0 because it's not in any *Asset collection* (in the *Assets* window). In this collection, it is assigned to slot 5, because it has 005 in the beginning of its name.
The video asset *002\_syncTest\_opus\_HAP.mov* video asset is assigned to slot 002 (because of the '002\_' in its name) and collection 1, because it's in an *Asset collection* called *001\_intro*.
### Manually filling the slots
To fill them manually, just drag an asset from *Asset* window manually.
To fill a *Mapping* collection slot, just drag from one of the mappings (screens, canvases, throwers...) to a slot.
And to fill a *Device* collection, alt + drag from a device node onto a slot.
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**Good to know:** The examples above focus primarily on *Asset* indexing, but the approach is the same for *Devices* and *Mappings*.
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