---
title: clock
framework: avfoundation
role: symbol
role_heading: Instance Property
path: avfoundation/avexternalsyncdevice/clock
---

# clock

A clock representing the source of time from the external sync device.

## Declaration

```swift
var clock: CMClock? { get }
```

## Discussion

Discussion This property returns NULL until the status reaches AVExternalSyncDeviceStatusActiveSync.

## See Also

### Inspecting a device

- [productID](avfoundation/avexternalsyncdevice/productid.md)
- [signalCompensationDelay](avfoundation/avexternalsyncdevice/signalcompensationdelay.md)
- [status](avfoundation/avexternalsyncdevice/status.md)
- [uuid](avfoundation/avexternalsyncdevice/uuid.md)
- [vendorID](avfoundation/avexternalsyncdevice/vendorid.md)