This article explains and details how to set up the different NTP features on your Ewon device.
Ewon Cosy, Ewon Flexy.
Have an access, locally or remotely, to your Ewon device.
IN THIS ARTICLE
NTP which stands for Network Time Protocol is a way to synchronize multiple network devices
on the same time (in UTC).
This is important for several domains:
- Encryption/Authentication with certificates: to check the validity of start/expiration date.
- Data logging: ensure your data/alarms timestamps are consistent from the origin to the
As of firmware version 13.1s0, there are 3 aspects of the NTP feature integrated in the eWON :
- NTP client : The Ewon retrieves its date & time from a remote NTP server.
- NTP server : The Ewon is the one distributing its date & time.
- NTP relay : The Ewon retrieves the date & time from a remote NTP server and distributes the date and time to LAN devices. It regroups the NTP client and server such as NTP relay = NTP client + NTP server
If the Ewon device has an access to Internet, the eWON device can connect to a remote NTP
server with a better time reference (e.g.: atomic clock) or just a single point to retrieve a precise
date & time.
The Ewon device can be an NTP server which means it can provide NTP synchronization on your
factory floor without an external source.
The Ewon device can also combine both solutions and become an NTP relay: it will retrieve the
date & time from a remote NTP server and transfer this date & time to its LAN devices.
The system wizard sets by default the Ewon device as an NTP client.
The following settings can be modified :
- Timezone : Sets the Ewon device in a specific timezone.
- Configure update of clock : The time of the Ewon device can be set manually by the user or updated via NTP (the Ewon retrieves automatically its time from a remote NTP server).
- NTP Server address : The URL of the remote NTP server. By default, “ntp.talk2m.com" is set. This field is shown only if “Update clock via NTP” is selected.
- Update interval : The time interval used to update the clock. This field is shown only if “Update clock via NTP” is selected.
- Datetime : The date and time set manually. This field is shown only if “Manually” is selected.
The configuration of the NTP through the advances menu is for Flexy only.
However, all parameters listed here can also be found in
Setup>System>Storage>Tabular edition>Edit SYSTEM cfg (in both Cosy and Flexy).
To find the corresponding parameters, please refer to this document.
The NTP client configuration can be performed by going to :
Setup > System > Main > General >Date & Time
These parameters are the same than the ones in the System Wizard.
The NTP server configuration can be performed by going to :
Setup > System > Main > Net services > NTP Server
The following parameter can be set :
- Enable NTP Server : Sets the Ewon devices as an NTP server to its LAN devices.
If the NTP client is not enabled then this NTP relay setting enables/disables only the NTP server of the Ewon.
The Ewon device can retrieve its time from a remote NTP server to set accurately its date & time.
The Ewon device can then propose this date & time to its LAN devices.
This concept is called the NTP relay as the Ewon is both an NTP client (retrieving the time from
outside) and an NTP server (providing the time to local network).
To activate the NTP relay, both NTP Client and NTP Server must be enabled.
The NTP client will update the Ewon system clock periodically. This is performed using a remote
The time difference between the Ewon device and the remote NTP server, before
synchronization, can be huge (some seconds, some minutes) and not monotonic (backward or
The Ewon device can handle that kind of problem because the Ewon is designed to have,
internally, a monotonic time.
But some devices cannot handle properly :
- Inconsistent data (timestamps mixed in the past/future)
To avoid this kind of problem and as the Ewon is used as an NTP server, the Ewon device ensures
to provide a monotonic time by speeding up/down the time to change the time in a smooth and
imperceptible way, instead of having a brutal time change.
Link to the original documentation : NTP Client – Server – Relay