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Multi Device Sync Tab

The Multi Device Sync (MDS) tab gives access to AWG output synchronization across multiple HDAWG and to the automatic timing synchronization of pulse counter and other measurement data. This tab is available on all HDAWG instruments.


  • Automatic timing synchronization across instruments
  • Periodic check of synchronization
  • Selectable instrument subgroup
  • Status display


The Multi Device Sync tab contains the controls and status information for synchronized measurements on multiple instruments. Whenever the tab is closed or an additional one of the same type is needed, clicking the following icon will open a new instance of the tab.

Table 1: App icon and short description
Control/Tool Option/Range Description
MDS Synchronize multiple instruments.

The Multi Device Sync tab shown in Figure 1 consists of the Available Devices section, a Status section, and a wiring diagram.

Figure 1: LabOne UI: Multi Device Sync tab

The Multi Device Synchronization feature provides an automated functionality to remove the clock offset of separate HDAWG instruments and align their output signals in time. Once synchronized, multiple instruments can be programmed with a single sequence program by simply extending the syntax of the LabOne AWG Sequencer language to higher channel numbers. This is described in AWG Sequencer Tab. Additionally, synchronization enables a correct simultaneous display of measurement data across instruments in the Plotter Tab.

The first prerequisite for automatic synchronization is that all instruments are connected to the same LabOne Data Server (see Connecting to the Instrument).

To make these connections, click on in the Config Tab to open the Device Connection dialog. Go to the Advanced view of this dialog and click on the Enable checkbox next to the corresponding entries in the Available Devices list. Once all instruments are connected, they are selectable in the Tree Selector of a newly opened Plotter tab allowing you to visualize their data simultaneously, though by default these data are not synchronized yet. The settings of multiple instruments can be accessed in parallel by opening a new Web Server session for each of them. This is done by opening a new browser tab and connecting to localhost:8006 or, respectively, and then double-clicking the respective instrument entry in the Available Devices list. With multiple instruments connected to the same Data Server, tabs that are available for several instruments will feature a device selector as shown in Figure 2.

Figure 2: Example of the device selector for the Device tab

The second prerequisite for automatic synchronization is correct cabling of the instruments explained in the diagram in Figure 3. The instruments should share the same external 10/100 MHz reference clock and communicate via the MDS connectors for absolute timing synchronization. The 10/100 MHz clock signal is distributed in a star arrangement, where the signal of an external clock generator is sent to the Reference Clk In connector of all instruments. It's important that all the cables that carry the clock from the source to the HDAWGs have the same length. On all instruments, the Clock Source in the Device Tab needs to be set to External rather than Internal. The bidirectional MDS connectors are to be connected in a loop arrangement, where MDS 1 of one instrument is connected to MDS 2 of the next instrument, and so forth, until the loop is closed.

Figure 3: Cabling for automatic synchronization of multiple HDAWG instruments

Once the cabling and the connectivity is set up correctly, automatic synchronization is started in the Multi Device Sync tab by checking the Enable button on the instruments in the Available Devices list, and then clicking on . The sequence assignment of the instruments (Leader, Follower 1, Follower 2,...) can be defined by the order in which the Enable button is clicked. This assignment has to agree with the way the cabling is made. It's important that MDS 2 of the Leader is connected to the MDS 1 of Follower 1, MDS 2 of Follower 1 to MDS 1 of Follower 2 and so on. If the order of assignment is not respected, an error about missing connectivity will be raised during the initial synchronization. The sequence is also relevant for addressing the instruments in an AWG sequence program. The Message display on the right will then report on the progress, and the Sync Status LED will turn green if the synchronization was successful. In that case, visualizing a time-dependent measurement of multiple instruments in the Plotter will demonstrate the timing synchronization.

Functional Elements

Table 2: Multi Device Sync tab
Control/Tool Option/Range Description
Start Sync Start the automatic synchronization of the selected devices.
Sync Status Indicates the status of the synchronization within this group. Green: synchronization successful. Yellow: synchronization in progress. Red: error (see message).
Message Displays a status message of the synchronization group.
Cabling This image shows how to connect the devices for device synchronization.
Phase Synchronization Reset phases of all oscillators on all synchronized devices.
Identify Device Make device's front LED blink