Calrec Argo S Startup Manual page 30

Synchronisation - Core
This page is accessed from the Devices
menu when a Core device's 'Sync' tab is
selected and appears as shown above
right for 'calrec-system'. It provides the
ability to synchronise the network clocks
of the devices by setting up PTP clocks
and determine how the AoIP interfaces
respond on the selected core. The two
PTP interfaces on the Core are located
on the front of the Control Module and are
described as PTP A and PTP B on the
synchronisation screens.
The sync page is split into 2 areas:-
The right hand area shows the Port Status
of each PTP interface with respect to the
master clock. The columns in this Port
Status table provide information about:-
- Port status indicators:- Green is active,
Red is not active.
- Primary and Secondary port identifiers
for each device i.e. PTP A, PTP B.
- Port statuses:- MASTER provides
a clock source for it's downstream
connections, SLAVE follows the clock
source that is in the Master state or it is
defined as FAULTY or passive which is
neither the master or a slave of a master,
or when no connection has been made.
- Offset (from Master):- this is a measure
of how accurately a slave synchronises
with a master clock.
- Mean Path Delay is the average time
taken for PTP frames to travel between
master and slave, a large mean path
delay is indicative of jitter and latency.
The left hand area displays the PTP
Grandmaster ID of the current clock
source. The settings to the right of this
allow the user to modify how each of the
interfaces will interact with the clock.
There are basic configuration settings and
advanced configuration settings which are
accessed from the 'Advanced settings'
button in the footer of the page.
Basic Synchronisation Settings
As shown above and below right:-
Domain: Multiple PTP clocks can exist on
the same network these are kept separate
by placing them in different domains.
The domain number (0-255) selects the
domain to be used.
30 ImPulse
IP Audio Routing & Mixing System
BASIC CORE SYNCHRONISATION
ADVANCED CORE SYNCHRONISATION
Priority: This value (0-255) is used in the
Best Master Clock Algorithm to determine
which AES67 device will become the PTP
Grand Master Clock in that domain.
Slave Only: This tick box is used to
prevent a device from establishing itself
as a Master and should be selected when
locking to an external PTP clock.
Advanced Synchronisation Settings
As shown below right:-
Priority 1: Same as basic Priority setting.
Priority 2: Backup Priority setting.
Modes: These transparent clock modes
calculate the required time it takes to
send traffic either from E2E (end to end)
or from P2P (peer to peer) and updates
the PTP time correction field as required.
Two Step: This improves the flexibility
of the synchronisation system by first
sending the sync message followed by a
separate time stamp.
Sync Interval: Time period between sync
messages which can vary from -7 to +1.
Announce Interval: Time period between
PTP announcement messages which can
vary from -3 to +4.
Announce Receipt Timeout: Number
of PTP intervals a device can miss before
timing out which can vary from 2 to 10.
Delay Request Interval: Time period
between PTP delay request messages
which can vary from -1 to +6.
Note:- In the images above the
Secondary AoIP port is not connected.
Start Up Guide