---
title: AVExternalSyncDeviceDelegate
framework: avfoundation
role: symbol
role_heading: Protocol
path: avfoundation/avexternalsyncdevicedelegate
---

# AVExternalSyncDeviceDelegate

Defines an interface for delegates of AVCaptureDeviceInput to respond to events that occur when connecting, calibrating, and disconnecting external sync devices.

## Declaration

```swift
protocol AVExternalSyncDeviceDelegate : NSObjectProtocol
```

## Topics

### Responding to device events

- [externalSyncDevice(_:failedWithError:)](avfoundation/avexternalsyncdevicedelegate/externalsyncdevice(_:failedwitherror:).md)
- [externalSyncDeviceStatusDidChange(_:)](avfoundation/avexternalsyncdevicedelegate/externalsyncdevicestatusdidchange(_:).md)

## Relationships

### Inherits From

- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### External synchronization

- [AVExternalSyncDevice](avfoundation/avexternalsyncdevice.md)
- [AVExternalSyncDeviceStatus](avfoundation/avexternalsyncdevicestatus.md)
- [AVExternalSyncDevice.DiscoverySession](avfoundation/avexternalsyncdevice/discoverysession.md)