This material describes special operating conditions related to:
To establish the accurate Ethernet system network time, the system does the following at power-up:
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requires the Ethernet module to boot
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uses the Ethernet module to obtain the time from the NTP server
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requires a predefined interval until time is accurate; user’s configuration determines how long before time is accurate
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may require several updates to achieve peak accuracy
Once an accurate time is received, the service sets the STATUS in the associated time service register.
The time-service clock value starts at 0 until fully updated from the module.
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Model
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Starting Date
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Modicon Quantum with Control Expert
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January 1st 1980 00:00:00.00
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Stop and Run have no effect on the accuracy of the clock.
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Stop and Run have no effect on the update of the clock.
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A transition from one mode to the other has no effect on the accuracy of the system Ethernet network time.
The status clock value associated with the time service register in the CPU is reinitialized after an application is downloaded or after an NTP server swap.
There will be two polling periods before the time is accurate.
Elsewhere in this section is information about the NTP configuration.
