System time

Applications in industrial automation depend on real-time operation, so it is crucial to always have your device set to an accurate date and time. Therefore, your PLCnext Control device contains a real-time clock (RTC). 

Factory default

PLCnext Control devices (except AXC F 1252) are usually set by default to UTC0 which is UTC±00:00 of the Coordinated universal time (UTC). So when starting up initially, the system time will be according to UTC±00:00.

Exception: The real-time clock of PLCnext Control AXC F 1252 comes without a buffer that would allow keeping the date and time settings. An automated time synchronization is highly recommended.

Note: Time stamps created by OPC UA server, DataLogger or Notification Logger are always according to UTC0.

Adjusting date and time

Most users will have to adjust the real-time clock on the device at minimum once. Depending on device and on the precision you need for your application, that might be a recurring task.

There are different methods available for setting the real-time clock on your device:

You can set the date and time on the device,
or
you can synchronize the device's clock with a computer. 		This way, the UTC0 value on your device is replaced by a specific date and time. It's improbable to set up other connected devices to the exact same date and time by this method, and there's no adjustment for time deviation due to the hardware and environmental influences. 
You can set your device to a local time zone. This way, the device's clock can regularly adjust to and from daylight saving time (DST) at that location. But even with the connected systems all set up by this method, they would be just approximately at the same date and time. There's no adjustment for time deviation due to the hardware and environmental influences. 
You can connect the device to a NTP server that regularly synchronizes the device to a reference clock. This approach allows selecting a set of network time protocol (NTP) servers to synchronize the real-time clock at a defined cycle. The current date and time for your device can be calculated with high precision, even adjusting for millisecond-level network delay. 

Setting date and time manually

Via the Web‑based Management

Available from firmware 2026.6

On the Date & time WBM 2 page, you can set the device's real-time clock to a specific date and time. The procedure is self-explanatory.

Via PLCnext Engineer

Setting a specific date and time
  • Connect PLCnext Engineer with the device as an admin user.
  • In the PLANT area, double-click on the PLCnext node.
    ↪ The PLCnext device editor group opens.
  • In the Online Parameters editor, select the Real time clock view.
  • To read the date and time from the device, click the  button.
  • Change the date and time in the input fields (see the circled ℹ for the input format).
  • To transfer the date and time to the controller, click the Write Values button button.
    ↪ The date and time are transferred to the connected PLCnext Control device.

Synchronizing with a computer

You can synchronize the system time of your device with the system time of a computer. The device will adjust its UTC±00:00 to the computer's system time.

  • Connect PLCnext Engineer with the device as an admin user.
  • In the PLANT area, double-click the device node.
  • In the Cockpit toolbar, click the  button. 

    ↪ The date and time are transferred to the connected PLCnext Control device.

Via shell commands

Note: Configuration via shell commands is not recommended by Phoenix Contact.
  • Connect via SSH to the device as an admin user.
  • Open the shell on your computer.
  • Request the current system time via the date command.
  • To set the date and time on your device, enter the shell command sudo date -s "YYYY-MM-DD hh:mm:ss" with the date and time.
    ↪ The date and time are transferred to the connected PLCnext Control device.

Setting a time zone

Via the Web‑based Management

Available from firmware 2026.6

  • Choose the Timezone in the drop-down menu:
    • Using a geographic time zone determined by continent and reference city, the device's real-time clock can regularly adjust to and from that timezone's daylight saving time (DST).
    • Using an offset to UTC±00:00 or a named time zone, any change in the local time zone will be ignored, so switching to and from to daylight saving time (DST) has to be done manually. 
      Hint: By typing "etc" into the input field, the drop-down menu scrolls to the bottom where you can choose a specific offset to UTC±00:00 or a named time zone.

Via the 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. The PLCnextBase library comes with instructions for importing and setting up, as well as detailed descriptions of the IEC 61131‑3 interface and all its components. After importing the library into PLCnext Engineer, it provides several functions, function blocks, and programs that are helpful in developing PLCnext-based automation solutions.

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 date and time settings by reading the timezone along with the local offset to UTC±00:00, and automatically switch to and from that timezone's daylight saving time (DST).

 

Managing date and time via an NTP server

It is possible to connect to network time protocol (NTP) servers. NTP server connections can be configured via Web‑based Management, PLCnext Engineer or via RSC services.

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 device.
For more features and differences to the former ntpd see the chrony project website. 

Up to firmware 2024.6

An NTP daemon is integrated into the operating system. Settings are done via the Date & Time legacy WBM page and saved in the ntp.conf configuration file on the controller. Note: During firmware updates to 2025.0 or newer, a pre-existing ntp.conf configuration on a device from a former firmware is not converted; neither are NTP configurations that have been made via PLCnext Engineer.

Setting up a connection to an NTP server

Via Web-based Management

Available from 2022.0 LTS

The controller's time setting by means of a network time protocol server can be configured directly on the controller via a Web-based Management page:

  • With the relaunched WBM 2 (firmware releases from 2025.0), the Date & Time WBM 2 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.

Via PLCnext Engineer

  • In the PLANT area, click on the PLCnext node.
  • In the Online Parameters editor, select the NTP view.
  • Enter the URLs for up to three NTP servers in the input field (separated by spaces).
  • Reboot the PLCnext device for changes to become effective.

Via shell commands

Available only with firmware 2022.0 LTS up to 2024.6

An ntpd (network time protocol daemon) is integrated into the operating system. If you prefer a Linux®-only tooling you can set up a server connection via shell commands.

  • Connect to the device as anadmin 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: 

 

See also

  1. Operating system
  2. Firmware directories
  3. Connecting to the controller
  4. Authentication failure handling
  5. User rights

 

 

• Published/reviewed: 2026-06-11  ✿  Revision 095 •