Download Premium and Atrium Using Unity Pro Ethernet Network Modules

Time Synchronzation Service
Using the Time Synchronization Service
Establishing
Accuracy at
Power Up
Before starting a system, the Ethernet network must be configured for a
predefined interval within which the accuracy is established. Accuracy is established
at power-upó the Ethernet module boots and then obtains the time from the NTP
server (see p. 229).
Several updates may be required to achieve peak accuracy. Once an accurate time
is obtained, the time synchronization service sets the STATUS (see p. 332) in the
associated time service register.
Obtaining and
Maintaining
Accuracy
The time service clock starts at 0 and increments until the Ethernet network time is
fully updated from the module.
Model
Starting Date
Premium with Unity
January 1st 1980 00:00:00.00
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z
z
Reinitializing the
Time Service
Register
Clock accuracy is not affected by issuing Stop/Run commands on the PLC
Clock updates are not affected by issuing Stop/Run commands on the PLC
Mode transitions do not affect the accuracy of the Ethernet network
After a download or an NTP server swap, the status clock value associated with the
time service register in the CPU is reinitialized.
Two polling periods elapse before an accurate time is re-established.
331