Fri Aug 23, 2024 9:31 pm
That does stink that that device won't instantly sync up. It's designed to.
So IEEE Standards Association describes IEEE 1588 as the protocol that enables heterogeneous systems that include clocks of various inherent precision, resolution, and stability to synchronize to a grandmaster clock.
According to SMPTE, SMPTE 2059, used in SMPTE 2110 system of standards used on the Blackmagic device, is an integral part of emerging professional IP video broadcast technology and standards.
The Blackmagic 2110 device lists using 3 Precision Time Protocols
IEEE 1588-2008 (PTP v2)
SMPTE 2059-1 – Defines signal generation based on time information delivered by the IEEE 1588 protocol.
SMPTE 2059-1 – Defines signal generation based on time information delivered by the IEEE 1588 protocol.
I’m just a camera director, but there are variable in hardware versus software derived PTP. Not sure which is used here or if it matters if there is an auto setting in follow mode based on feedback from a network maybe?
Say for example, The System Clock is at 9:00:00. The Second Device keeps track of the offset time between the system and itself. The Second device clock thinks it’s 9:00:10, so we have a 10-second offset. To keep it simple, we’ll imagine we have a one-second delay to transfer packets from the System Clock to the Second Device clock.
The System Clock periodically sends a sync message. Let’s say it sends a sync message at exactly 09:00:00. This moment is the T1 value. We now have two options:
• If your hardware supports PTP:
o The exchange is called a one-step message exchange, and we only send a sync message that contains the T1 value.
• If however, PTP is done in software:
o PTP uses a two-step message exchange because of additional delays.
o This means that after the sync message, we send a follow-up message immediately, including the T1 value.
o The T1 value won’t be in the sync message.
o The follow-up message means, “The sync message you just received was sent at the time specified in the T1 value”.
With so much going on behind the scenes, it would be great to see a list of tested network devices, menu profiles, and cabling for the 2110 IP Converter 3X3G. What are we missing here?
It does still look like a great device for live events even if it’s not timed to your existing IP network down to the sub-microsecond. It saves on cable runs and the format is designed as a low-latency system for production facilities.