A__mic8 / A__digital8 User Guide
Version: 10.0.0/4
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11. The RAVENNA Web UI
11.9
Defining the PTP Properties
1.
From the
Sync
area, click on
PTP
to open the 'PTP Properties' window:
2.
Use the fields to type in a value or select a menu option.
3.
If you make a change, select
Apply
to confirm (or
Cancel
).
Please refer to the
for a more detailed explanation of PTP and how it should be
implemented. Here we will provide a general description of the parameter fields.
Ø
Slave only
The
Slave only
option determines whether the device will run in Slave only or master-slave mode.
If
Slave only
is enabled, then the device is forced to operate as a PTP slave at all times. The screenshot above
shows the default parameter values associated with this mode.
If
Slave only
is disabled, then the device will operate in PTP master-slave mode. In this mode, the PTP priorities
set within the device itself and all other streaming nodes determine the current PTP master.
Ø
Prio1 and Prio2
PTP uses a master-slave approach in which all master-capable devices elect the best master, called the
grandmaster, according to a common algorithm known as the “Best Master Clock Algorithm”. The algorithm
compares the following parameters in turn:
·
Prio1
- the lower the number, the higher the priority of the device.
·
Clock Class
·
Prio 2
- as for Prio 1.
·
MAC Address
For example, if there is no
Prio1
available, then all devices on the network look at the
Clock Class
, then
Prio2
and finally the
MAC address
.
Note that only the
Prio1
and
Prio2
values can be adjusted from the RAVENNA Web UI. The
Clock Class
is not
available but may be used by a third-party grandmaster if one is installed.
Ø
DSCP
The
DSCP
field assigns a DSCP (differentiated services code point) or quality class to the PTP clock stream. The
default setting is
56
.
Ø
Other Properties
The values within the remaining fields -
Domain
,
Announce Interval
,
Sync Interval
and
Delay Mechanism
-
vary depending on the PTP profile in use. See the
