System time

Default time zone

All PLCnext Control devices are set by default to UTC0 which is UTC±00:00 of the Coordinated universal time (UTC).

Note: Time stamps created by OPC UA or DataLogger are always UTC0.

Using the Network Time Protocol

It is possible to connect to Network Time Protocol (NTP) servers, or to start your own server. NTP servers can be configured via PLCnext Engineer or via RSC services.

Valid from firmware 2025.0

A chrony daemon is integrated into the operating system. Settings are done via the Date & Time WBM 2 page and saved in the chrony.conf file on the controller.
For more features and differences to the former ntpd see the chrony project website.

Note: Manual configuration is not recommended by Phoenix Contact. Use the Web-based Management page or the PLCnext Engineer for settings.

NTP configuration via Web-based Management

Available from 2022.0 LTS

The controller's time setting by means of the Network Time Protocol can be configured directly on the controller via a Web-based Management page:

with WBM 2 (Firmware releases from 2025.0), the Date & Time page is largely self-explanatory
for the legacy WBM (Firmware releases 2022.0 LTS up to 2024.6) see the Date and Time WBM page description

Setting up an NTP server via PLCnext Engineer

In the PLANT area, click on PLCnext
In the Online Parameters tab, select the NTP section
Enter up to three NTP servers (separated by spaces) in the input field
Reboot the PLCnext device for changes to be effective

Setting up an NTP server via shell commands

Valid only with firmware 2022.0 LTS up to 2024.6

An ntpd (Network Time Protocol daemon, see ntp.org) is integrated into the operating system.

To have sufficient rights to modify the data, log on to the controller as the admin user.
Navigate to the /etc/ directory.
In the ntp.conf configuration file, specify IP addresses and names.
To restart the NTP daemon, execute the command sudo /etc/init.d/ntpd

Additional information:

The PLCnext Runtime System already contains the NTP utilities (e.g. ntpq and ntpdc) for diagnostic and monitoring purposes.
Find a general overview to the Network Time Protocol daemon (ntpd) in the developer's introduction.
Find a detailed description of the configuration options in the developer's documentation.

NTP and time settings via PLCnextBase library

Another way to set the system time is the PLCnextBase library, provided in the PLCnext Store for free and without needing a license. After importing this library into PLCnext Engineer, it provides several functions, function blocks, and programs that are helpful in developing PLCnext-based automation solutions. It comes with instructions for import and setup, as well as detailed descriptions of the IEC 61131‑3 interface and all components.

For the system time, the PLCnextBase library depends on the native Linux® features. After importing this library in PLCnext Engineer, you can work with local time settings by reading the time zone along with the local offset to UTC, and automatically switch to and from daylight savings time.

Note: Time stamps created by OPC UA or DataLogger are always UTC0.

Setting the real-time clock

You can set the system time using the PLCnext Engineer software. Access to the controller with PLCnext Engineer requires authentication with a user name and password.

Defining RTC parameters

In the PLANT area, click on PLCnext.
In the Online Parameters tab, select the Real time clock section.
Enter the desired values in the corresponding input fields (see the circled ℹ for date formats)

Synchronizing with the host system time

You can write the current system time of your host computer to the real-time clock on the controller:

Open PLCnext Engineer and start a project template corresponding to your firmware version on the controller.
In the PLANT area, unfold the project branch and double-click the device.
In the Cockpit tab, click the button and connect to the controller as the admin user.
In the Cockpit tab, press the clock-shaped button.

↪ The controller's clock matches the host system's clock.

Note: The controller will adjust to the host system time as the controller's UTC0 time and ignore any given offset or time zone. Currently, the only way to work with an offset to UTC0 or with a specific time zone (which automatically switches to/from daylight savings time) on PLCnext Control devices is to use the PLCnextBase library out of the PLCnext Engineer.

Setting the system time via shell commands