I learned something new today; the first fax machine was built in 1860; and using the Nodal Clock for more accurate timestamping of real-time media IP signals and future event handling.
When transmitting an image from a sender to a receiver some notion of synchronization is required. In the 1860s Giovanni Caselli invented the Pantelegraph (a fax) that used a pendulum clock to regulate the transmitter’s scanning stylus and the receiver’s writing stylus.
In our day, “black-burst sync” and “tri-level sync” were used to align video signals in a facility. Now with Ethernet/IP taking the reins, synchronization may be achieved with common nodal clocks. The essence is for a “slave node” to lock its clock to a “master node” clock. Common node clocks can be used to create sync as will be shown. The SMPTE ST 2059 family of standards and the IEEE-1588 V2 Precision Time Protocol (PTP) standard are the basis for facility clocking and signal synchronization using IP networks.
