NTP time servers

NTP (Network Time Protocol), is used to synchronize computer system clocks via packed based TCP/IP-Networks. For more Information on NTP see Network Time Protocol or Meinberg: information on NTP.

An external NTP time server needs to be configured in DHD devices for having the right system time. DHD devices can work without a NTP time server configured. The following features only work with a correctly configured NTP time server:

  • Clock elements on TFT displays: without a correct time server the clock elements will be empty and will not show any time.
  • System time for system state and debugging: system time will start at January 1, 1970, 0:00am each time the system is booted. This time information is provided in any system state. This will make it hard to debug DHD systems.
  • Clock logics: will fall back to system time and trigger at the system time starting at January 1, 1970. 0:00am after reboot.
  • Temporary licences (demo licences): will be shown in system state but they will not work without a correct time server.

You can configure the connection to a time server by using Communication Server (since Version 9.1) or DHD Maintenance (MT5) on older versions.

To connect a time server to a DHD device using DHDCS, follow these steps:

  1. Open DHDCS on a computer that is connected to the DHD network.
  2. Click on the DHD device you want to connect to the time server. Then open the Device menu and select Network Config.
  3. The Network Config window opens.
    Network Config window
  4. In the Time area enter the IP address of the time server in the Primary Time Server box. Depending on your chosen time server you may need to enter some further settings. For that click Setup time zone and DST … to be able to enter a general time zone offset and if necessary the settings for the daylight saving time.
  5. Click Send in the Network Config window.
  6. If the NTP time server is working correctly, the DHD device will sync its system time to it.

It can take a while (up to 15 minutes) until the DHD device syncs to the NTP time server. To speed things up you can perform a System Reboot of the device via Communication Server (since Version 9.1) or Maintenance or MT5 on older versions.

With 52/XC2, 52/XD2, 52/XS2 cores you can define two additional time servers. If the primary time server is not available, the core will use Additional Time Server 1. If Additional Time Server 1 is not reachable, the core will use Additional Time Server 2.

Although DHD audio is not responsible for your IT infrastructure, we have two suggestions to provide a time server for your DHD network.

DHD audio is not responsible for providing a correct NTP time server. When in doubt always contact your IT department first.

Meinberg NTP Software

We recommend the Meinberg NTP software. You can download it at Meinbergglobal.com. It is easy to configure and has proved to run very stable. Follow the installation instructions provided by Meinerg and make sure to have the required ports opened in your firewall configuration.

Windows Services

You need to configure a computer with two network interfaces. Configuration will be done in two steps:

  1. Configure the first interface for the public network (e.g., office network, internet connection)
  2. Configure the second interface for the DHD network

DHD network is the network where the DHD devices are connected. This network should be separated from a office network. See Network specifications for more information on network architecture recommended by DHD audio.

Configure time sync for the Windows PC

The Windows PC has to be connected and synced to a time provider.

  1. The Windows service Windows Time must be running. It provides the NTP time for external devices.
  2. Go to Date and Time Settings: Internet time > Automatically Synchronize > Enter IP of network time server > Refresh (if necessary try multiple times) - Message Successfully synchronized [..] appears

Make sure the UDP Port 123 is not blocked by a firewall.

Configure sync for DHD

Now the DHD device can be configured. Follow the instructions in the section above Connect DHD device to time server.


  • Network settings of the DHD device have to fit with the settings on the second Network adapter.
  • The IP address of the time server is the IP of the PC network adapter attached to the DHD network. This IP address needs to be entered at the DHD Maintenance Network Config page.
  • Do not forget to reboot the DHD device.
Trouble-shooting for time server configuration
  • Is the w32tm (Windows Time) service already configured as server? - Check registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time\TimeProviders\NtpServer\, key enabled DWORD must be 1 (hex).
    • If this is not correct: change to 1 and restart the w32tm service
  • Is the Time Server trustworthy? Check registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time\Config, key AnnounceFlags is by default 0x0a, can be set to 0x04. This will make the time server always trustworthy, even if the provided time is invalid
Check if the time server is working correctly
  • On your computer, go to Start and open cmd application.
  • Use the w32tm /stripchart /computer:localhost command. This compares the system time with another time server (/computer:) in the network.
    • example: w32tm /stripchart /computer: or w32tm /stripchart /computer:ptbtime1.ptb.de
  • with /computer:localhost can be checked, if the internal time server is also running. (Time difference is then 0)
  • If an error is returned, time server is not running or has configuration problems