Extron Electronics Dante Controller - Manual (Page 30)

Dante Controller User Guide
Copyright © 2013 Audinate Pty Ltd. All rights reserved. -30-
Preferred Master
(checked or
unchecked)
Device may act as master clock
Slave only Device is not capable of becoming a PTP master
Not Supported Setting of clock role is not supported by this device
Not Available Clock Role information is not available for this
device
Checking 'Preferred Master' raises the priority of the device in the master clock election. If only one device
on a particular clock domain has this box ticked, it ensures that the selected device becomes master clock
(for the relevant clock domain). When multiple devices have their Preferred Master box ticked, the master
will be elected from within that group. This is a convenient method of controlling the group of devices from
which the master can be selected.
n
Slave To External Word Clock:
o Where a device can be slaved to an external Word Clock, the value 'Yes' (and a check box) will
appear in this column. When checked, this will force the device to derive its local clock from the
external word clock source. This will also ensure that this Dante device becomes master clock
for the relevant clock domain (unless another device has 'Preferred Master' selected). It is not
normal practice to configure more than one device per clock domain with an external clock
source. In this case, the user is assumed to have synchronized external word clock sources
(e.g. house clock).
o Where a device is shown with a checkbox and the text 'Yes' but the checkbox and text is greyed
out, it means that the Dante device
can be slaved to an external word clock, but it cannot be set
directly from Dante Controller - it must be done via the host device user interface, or via some
other method (e.g. third-party control software). If the checkbox is populated, it means that the
Dante device is currently slaved to the external clock.
o Where a device does not support slaving to an external Word Clock, the value in this column will
be 'Not Supported'.
Note: Older Dante devices may not have the ability to report their clock status. In such cases,
regardless of whether they are master or slave or have some other status, their status will be shown
as “Not Available”.
Clock Domains
Dante Devices that are not configured with sample rate pull-up/down operate on the default clock domain,
using the default clock. Devices that are configured with sample rate pull-up/down operate on separate
'clock domains', which have their own dedicated PTP clocks, adjusted to account for the pulled up/down
sample rates.
Clock domains are not physically separated, they all exist on the network simultaneously. Devices with
pull-up/down synchronise to the appropriate clock for their pull-up/down setting, and ignore other clocks.
Those devices are shown with the relevant pull-up/down value against their Clock Status in the Clock
Status tab.
Dante devices can only transmit audio to, and receive audio from other devices on the same clock domain.
For example, a device with zero sample rate pull-up/down operates on the default clock domain, and
cannot transmit audio to, or receive audio from any devices on the +4.1667% clock domain, or the -1%
clock domain, etc.