User manual
www.merging.com/horus Page 35
Horus User Manual
The IO and Synchronization menu is where the user can select the source of the Horus reference clock.
It is essential that these settings are configured correctly in order to ensure a clean audio signal through
the Horus unit.
Reference Source Choose the desired sync source by pressing on the respective Reference
source.
Available Reference Sources are: MADI, Sync or AES
Reference navigation Selecting a Reference with multiple choices (such as Sync or AES) will enable
the source navigation. The navigation is performed from top to bottom and will
cycle through in this order at each consecutive press. The selection of another
Reference Source will re-select the top entry in the list by default.
PTP Clock The Precision Time Protocol (PTP) is a protocol used to synchronize
clocks throughout a computer network. Also known as IEEE 1588, it is a
protocol designed to synchronize real-time clocks in the nodes of a distributed
system that communicates using a network. RAVENNA is based on and uses
V2 of this IEEE standardized protocol. PTP Clocks allow for time resolution to
the Nanosecond.
Master: indicates that the current Horus is the PTP Master
Slave: The Horus is slave to another PTP Master
The Horus will always try to be the PTP Master. If multiple Horus’ are used in a
network environment, the Horus set in this order will have the PTP Master
priority, using the Best Master Clock Algorithm (BMCA):
1. Video sync
2. Word Clock
3. AES
4. MADI
5. Internal
6. RAVENNA (always slave unless there is no PTP master available)
Sync Color table: Dark Blue: Signal present Red: Unlocked
Light Blue: Signal valid Yellow: Locking
Black: No Signal Green: Locked
Note: When two or more Horus are connected together through an Ethernet network, one of them will always be
automatically selected as master, the other Horus' will be forced into slave state and therefore will not be
synchronized to wordclock or audio input. However, this is not a problem since all Horus' will be synchronized.
Status: LTC IN: Corresponds to the incoming LTC frame rate