Multi Device Sync Tab¶

The Multi Device Sync (MDS) tab gives access to the automatic timing synchronization of measurement data from multiple UHF instruments. This functionality and tab is available on all UHF instruments.

Features¶

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

Description¶

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.

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 UHF instruments. This enables a correct simultaneous display of their data in the Plotter Tab and helps when analyzing recorded data. In multi-channel applications that require sub-microsecond timing precision, the user can therefore benefit from having synchronized data from the start, rather than having to manually measure and compensate the clock offset in post-processing.

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 127.0.0.1:8006, 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 10 MHz reference clock and communicate via the Ref / Trigger connectors for absolute timing synchronization. The 10 MHz clock signal is distributed in a star arrangement, where the signal of an external clock generator is sent to the Clk 10 MHz In connector of all instruments. On all instruments, the Clock Source in the Device Tab needs to be set to Clk 10 MHz rather than Internal. The bidirectional Ref / Trigger connectors are to be connected in a loop arrangement, where Ref / Trigger 1 of one instrument is connected to Ref / Trigger 2 of the next instrument, and so forth, until the loop is closed.

Note

Alternatively to using an external 10 MHz clock source, it’s possible to distribute the Clk 10 MHz Out signal from the leading instrument to the Clk 10 MHz In connector of all following instruments and the leading instrument using a 1-to-N power divider and cables of equal length. For a large number of instruments, a clock distribution amplifier rather than a power divider is required.

Figure 3: Cabling for automatic synchronization of multiple UHF 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. 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