{"id":22212,"date":"2016-02-16T17:16:33","date_gmt":"2016-02-17T01:16:33","guid":{"rendered":"http:\/\/lifeboat.com\/blog\/2016\/02\/time-transfer-in-networked-systems"},"modified":"2017-06-04T20:10:52","modified_gmt":"2017-06-05T03:10:52","slug":"time-transfer-in-networked-systems","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2016\/02\/time-transfer-in-networked-systems","title":{"rendered":"Time Transfer in Networked Systems"},"content":{"rendered":"

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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.<\/p>\n

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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\u2019s scanning stylus and the receiver\u2019s writing stylus.<\/p>\n

In our day, \u201cblack-burst sync\u201d and \u201ctri-level sync\u201d 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 \u201cslave node\u201d to lock its clock to a \u201cmaster node\u201d 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.<\/p>\n

The fundamental metrics of synchronization are time, frequency and phasing. From Fig. 1, each node has an individual clock with a time of day (ToD with date) that is governed by a frequency source or \u201ctime base.\u201d By way of example, the time base may be 60 cycles per second (Tp = 1\/60) or some other constant value. The signal is shown as a sine wave, but other periodic signals will do. Clock 1 is typically locked to a GPS time source in some manner.<\/p>\n

Read more<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

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 [\u2026]<\/p>\n","protected":false},"author":395,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-22212","post","type-post","status-publish","format-standard","hentry","category-futurism"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/22212","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/395"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=22212"}],"version-history":[{"count":2,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/22212\/revisions"}],"predecessor-version":[{"id":68429,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/22212\/revisions\/68429"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=22212"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=22212"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=22212"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}