Multi-Device Synchronization (MDS)
Do you have an application that requires multiple synchronized signal input and output channels? If yes, you probably know that stacking a few instruments is often not sufficient.
Full synchronization includes stable and well-defined phase relationships between the various reference clocks, the ability to synchronize the signal outputs at defined times, and the alignment of time stamps and sampling rates for the recorded signals. The ideal solution is a single user interface or API orchestrating the entire instrument assembly.
Zurich Instruments is committed to providing a comprehensive approach to measurement instrumentation with scalability in mind. LabOne® enables multi-device synchronization (MDS) for up to 8 instruments, and allows users to access them through a single graphical user interface and API session.
MDS Key Features and Operating Principle
- Clock synchronization of all instruments to one master clock
- Synchronized time stamps and sampling rates of measurement data
- Sample-wise synchronization of all output channels
- MDS module in LabOne to measure multiple devices simultaneously
- AWG linked mode to control the output of several AWG instruments from one single sequencer program with distributed execution
Example: multi-channel measurement automation with the Sweeper tool
Simultaneous measurement of several input signals facilitates and improves the characterization of multi-port networks. In order to obtain the frequency response of a multi-port network, one port is excited and all other ports (including the driven one) are measured. With the Sweeper tool enhanced by the MDS module, it is possible to measure the complete frequency response of a complex multi-port network in one sweep displayed by a single LabOne user interface or LabOne API session controlling several instruments. The figure below shows the frequency response of a 4-port network measured in a single sweep with two synchronized UHFLI Lock-in Amplifiers.
All involved instruments share the same 10-MHz reference clock to have a common clock speed. All instruments also need to be connected in a chain of trigger signals. By starting the MDS, LabOne executes the following sequence of steps:
- Adjust the reference clock of the slave instruments to the master clock or to an external source.
- Identify the position of each instrument in the chain of trigger signals.
- Measure the cable delay between instruments.
- Adjust the clock in each instrument while taking into account the measured cable delays.
At the end of the sequence all instruments have the same clock time, i.e., synchronous time stamps of individual samples.
Every application requiring multi-channel signal generation and/or detection may benefit from MDS, especially when multi-channel signals must be generated and/or measured synchronously. This applies to the following research areas and techniques:
- Multi-qubit quantum computing
- NMR measurements
- Multi-sensor measurement systems, e.g. Hall effect material characterization and sensing
- Multi-channel boxcar averaging
- Multi-point impedance technique in microfluidics
- Phased-array radars
- Noise reduction by cross-correlation
MDS-enhanced LabOne features
- Sweeper: Scan a parameter for one instrument and measure the response over multiple channels and instruments in a way that is fully synchronized with the sweep parameter changes.
- DAQ: Measure time-domain signals and record images based on trigger signals across multiple instruments with accurate sample alignment.
- Plotter: Display signals from multiple instruments simultaneously with time-stamp alignment.
- Spectrum: Compare signal spectra from various instruments.
It is possible to synchronize multiple instruments from the same series. Each platform has its own cable configuration for reference clock and trigger signals.
Multiple MFLI Lock-in Amplifiers and/or MFIA Impedance Analyzers can be synchronized by connecting the 10 MHz clock output of one instrument to the next one. One instrument acts as the master trigger source, from which trigger signals are then distributed to all other instruments including the master (see diagram).
|10 MHz Clock||Series||BNC|
The HF2LI Lock-in Amplifier has a specific signaling for synchronization based on RJ45 connectors to share trigger and clock signals (see diagram).
On the UHF platform, MDS can bring considerable benefits as the instrument has both the AWG and lock-in functionalities. The clock signals are distributed in a star-like fashion, with one instrument acting as the master (or, alternatively, using an external 10 MHz reference clock): the trigger signals are then shared through a loop including all instruments (see diagram).
|10 MHz Clock||Star||SMA|
Up to 8 HDAWG Arbitrary Waveform Generators (corresponding to 64 AWG channels) can be synchronized using MDS. The 10/100 MHz clock is distributed in a star-like fashion thanks to an external clock source. Time-stamp synchronization is achieved through a loop that includes all instruments and makes use of specific MDS trigger ports (see diagram). Synchronizing more than 64 channels requires the PQSC Programmable Quantum System Controller.
|MDS 1/ 2||Loop||SMA|
|10/100 MHz Clock||Star||SMA|
MDS goes one step further compared to having the clocks of different instruments running at the same speed. MDS assures that all instruments have the same time base, i.e., synchronized time stamps for recording and synchronized AWG output samples.
Synchronization of oscillator phases involving HDAWG instruments and the MF series (such as multiple MFLI Lock-in Amplifiers and/or MFIA Impedance Analyzers) can be achieved automatically using the MDS module. For other instrument platforms, users must perform the synchronization manually.
No, External Reference is a feature of lock-in amplifiers that makes it possible to obtain a demodulation frequency from an external signal. This typically involves a PLL to map the external frequency to an internal numerical oscillator. With MDS, the clock synchronization enables demodulation on multiple instruments with a stable phase relation, but the relative oscillator phases between instruments must be manually adjusted each time that the frequencies are changed.
Since each instrument platform has its own clock speed, MDS can only synchronize instruments from the same series such as multiple MF instruments. Nevertheless, it is possible to synchronize the HDAWG and multiple UHF instruments.
|Number of devices||Up to 8||Up to 4||Up to 8||Up to 8|
|Time precision||< 10 ns||< 200 us||< 1 ns||< 1 ns|