Rockwell Automation 1783-Mxxx Stratix 8000 and 8300 Ethernet Managed Switches User Manual - Manual (Page 166)

166 Rockwell Automation Publication 1783-UM003I-EN-P - March 2014
Chapter 5 Manage the Switch via the Studio 5000 Environment
Time Sync Information Use the Time Sync Information tab to view current information about the real-
time clocks in the network. The CIP Time Synchronization protocol provides a
standard mechanism to synchronize clocks across a network of distributed
devices.
TIP The CIP Sync Time Synchronization feature supports both Boundary and End-
to-End Transparent mode. End-to-End Transparent mode synchronizes all
switch ports with the Grandmaster clock using the IEEE 1588 V 2 End-to-End
Transparent clock mechanism, and is the preferred mode.
TIP The information on this tab is not displayed if you are offline or the CIP Sync
Time Synchronization feature is disabled.
Field Description
CIP Sync Time Synchronization Displays whether the Precision Time Protocol is enabled or disabled on the device.
UTC System Time Displays the current system time in units of microseconds.
Grandmaster Clock Displays clock property information for the Grandmaster clock. The Grandmaster clock is the most precise clock source in the network.
Identity Displays the unique identifier for the Grandmaster clock. The format depends on the network protocol.
Class Displays a measure of the quality of the Grandmaster clock. Values are defined from 0…255 with 0 as the best clock.
Accuracy Indicates the expected absolute accuracy of the Grandmaster clock relative to CIP Sync time synchronization epoch (31 December, 1969
23:59:51.99918 UTC). The accuracy is specified as a graduated scale starting at 25 ns and ending at greater than 10 seconds or unknown.
For example, a GPS time source has an accuracy of approximately 250 ns. A hand-set clock typically has an accuracy less than 10 seconds.
The lower the accuracy value, the better the clock.
Variance Displays the measure of inherent stability properties of the Grandmaster clock. The value is represented in offset scaled log units. The
lower the variance, the better the clock.