The synchronizes the clock in the BMENOP0300 module to that of the network time server. Typical time service configurations utilize redundant servers and diverse network paths to achieve high accuracy and reliability.
Use the time service for:
Time Synchronization Service Features
Features of the time synchronization service include:
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periodic time correction obtained from the reference-standard time server
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automatic switch-over to a backup time server if communication with the primary time server is interrupted
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availability of a function block for application programs that can read the accurate clock, and let project events or variables be time stamped
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configurable local time zone, including daylight savings time
NOTE: Broadcast frames for clock synchronization are not supported.
Time Synchronization Process
The NTP client sends requests to the NTP server in the network to get the reference time for synchronizing the local time of the Ethernet communication module:
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Stage
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Description
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1
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Through an Ethernet network, an NTP client requests a time synchronization signal from an NTP server.
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2
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The NTP client calculates the correct time and stores the value.
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On an Ethernet network, confirm that all controllers are synchronized with the same NTP server.
To establish the accurate Ethernet system network time, the system performs the following at power-up:
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The BMENOP0300 module powers up.
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The BMENOP0300 module obtains the time from the NTP server.
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The service requires the requests to be sent periodically to obtain and maintain accurate time. Your Polling Period configuration partially determines the accuracy of the time.
After the accurate time is received, the service sets the status in the associated time service diagnostic.
The time service clock value starts at 0 until fully updated from the BMENOP0300 module.
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Model
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Starting date
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Modicon M580 with Control Expert
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January 1st 1970 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 operating mode to another has no effect on the accuracy of the Ethernet system network time.
The status clock value associated with the time service register in the CPU is re-initialized after an application is downloaded or after an SNTP server swap.
There will be two polling periods before the time is accurate.
Time Synchronization Configuration Settings
The Communication Settings → SNTP tab presents the following configuration settings:
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Setting
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Action
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NTP Server Configuration:
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Primary NTP Server IP Address
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Enter a valid IP address.
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Secondary NTP Server IP Address
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Enter a valid IP address.
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Polling Period
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The polling period is the time (in seconds) between updates from the SNTP server. To obtain optimal accuracy (and if your network allows), reduce the polling period to a small value. The default is 5 seconds.
Valid values include:
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minimum = 1 s
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maximum = 120 s
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Time Zone:
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Time Zone
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Select the desired time zone from the drop-down list. The default value is your current system time zone (as found in Windows). You can also select Custom Time Zone.
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Time Zone Offset
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If you select Custom Time Zone, enter a value in the range of (24 hours * 60 minutes - 1) [1-minute step].
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Daylight Saving:
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Automatically adjust clock for daylight saving change
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De-select (default): If you do not want the clock to automatically adjust for daylight saving, do not select the check box. In the Start Daylight Saving and End Daylight Saving fields, enter the month, day of week, and occurrence range from the respective drop-down lists.
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Select: If you do want the BMENOP0300 module to automatically adjust for daylight saving, select the check box. The Start Daylight Saving and End Daylight Saving fields are disabled because their times are automatically changed in the spring and fall every year.
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Start Daylight Saving
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If you do not select the automatic daylight saving check box, select values for:
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End Daylight Saving
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If you do not select the automatic daylight saving check box, select values for:
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CPU Time Update:
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Update CPU time with this module
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NOTE: Only one BMENOP0300 module can be configured to perform the update of the CPU clock.
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When you finish editing time synchronization configuration settings, click Apply to save your edits.
