---
title: "startController(onExistingFabric:)"
framework: matter
role: symbol
role_heading: Instance Method
path: "matter/mtrcontrollerfactory/startcontroller(onexistingfabric:)"
---

# startController(onExistingFabric:)

## Declaration

```swift
func startController(onExistingFabric startupParams: MTRDeviceControllerStartupParams) -> MTRDeviceController?
```