User manual

228 Rockwell Automation Publication MOTION-UM003F-EN-P - March 2015
Appendix A CIP Drive Module Properties
Time Sync Tab
When you are online with the controller, you can review the time
synchronization status data that is related to the network. When you are offline,
no values display.
Figure 11 - Time Sync Tab
Table 34 - Time Sync Tab Descriptions for the Grandmaster Clock
Parameter Description
Identity Specifies the unique identifier for the Grandmaster clock. The format depends on the
network protocol. Ethernet network encodes the MAC address into the identifier
while ControlNet and DeviceNet networks encode the vendor ID and serial number
into the identifier.
Class Specifies a measure of the quality of the Grandmaster clock. Values are defined from
0 … 255 with zero as the best clock.
Accuracy Indicates the expected absolute accuracy of the Grandmaster clock relative to the PTP
epoch. The accuracy is specified as a graduated scale that starts at 25 ns and ends at
greater than 10 seconds or unknown. The lower the accuracy value, the better the
clock.
Variance Displays the measure of inherent stability properties of the local clock. The value is in
offset scaled log units. The lower the variance, the better the clock.
Source Specifies the time source of the Grandmaster clock (for example, GPS, NTP, and hand).
Priority1/Priority 2 specifies the relative priority of the Grandmaster clock to other
clocks in the system. These fields can be used to override the best master in the
system.