janitza UMG 604-PRO, User Manual And Technical Data, Page: 53 / 87

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UMG 604-PRO
48
INFORMATION
·
A Modbus address list including all the PTP parameters of your device can be found in
the download area at www.janitza.de.
·
Specifications for PTP (Precision Time Protocol) can be found in IEEE Standard for a
Precision Clock Synchronization Protocol for Networked Measurement and Control
Systems (IEEE Std. 1588-2008).
·
The device supports PTP according to the default PTP profile Annex J IEEE 1588-2008
with the profile ID 00-1B-19-00-01-00.
11.10.3 Example: PTP timing according to IEEE 1588-2008 and clock types
Ordinary clock
(OC)
Simple clock (one port, measures one client) that is connected with a master as
the slave and synchronizes its time with the master.
Boundary clock
(BC) Clock that contains several “ordinary clocks” (several ports) and, as the master,
synchronizes several slaves with its time and transports this beyond a network
boundary. The “boundary clock” can also be connected to a master as a slave
and synchronize its time with the master.
Transparent clock
(TC) Clock that does not actively intervene in the time synchronization; it is more a
hardware item that transmits time synchronization data packets (e.g. a network
switch). “Transparent clocks” can also correct the time stamp within the data
packet by the dwell time within the hardware, if needed.
Grandmaster clock
(GC) The grandmaster clock is an “ordinary clock” that has access to GPS or ano-
ther very accurate time and provides this time for all subordinate nodes.