Lithe is producing a family of web-centric instruments that incorporates precision timekeeping hardware within the measurement engine. By elevating time to an essential parameter of all measurements, Lithe instruments add a new dimension to data taking.
Multichannel Time Interval and Timestamping Instrument (MTI)
The MTI product line will see a family of instruments that combine parallel time-to-digital converters (TDC) with a hardware-assisted PTPv2 client. User inputs are monitored for events (edge-triggered). Event arrival time is timestamped in hardware. The instrument includes built-in capabilities to display event timing statistics include histograms and stability analysis. A deep event log stores events over an extended measurement period for improved statistical convergence. Timestamps and statistical measurements are available via 1 GbE port and hdf5 file downloads. The first instrument to be released has 5 parallel inputs.
The MTI maintains two separate hardware timebases. The first timebase is used to record events using an absolute timebase synchronized to network time. For optimum time-transfer precision, the MTI include a 1 GbE port with a hardware-assisted PTPv2 client. The PTPv2 client is integrated directly within the measurement engine to ensure the highest possible time accuracy.
In addition to the absolute timestamping, the MTI measures relative arrival time of user events with dedicated TDCs. The result is time delay measurements with error of <100 ps (RMS) on all input ports. The relative time delay between channels uses a dedicated timebase to ensure short-term accuracy is not impacted by network time-transfer noise.
By simultaneously logging event arrival time on both timebases, the MTI can provide time measurement capabilities over a wide range of measurement periods. Furthermore, the MTI includes an integrated GUI for monitor, control and data acquisition. The GUI uses web-application technology that works on most web-browsers. Data analysis capabilities are provided to visualize your data. This includes histograms, statistics and stability analysis.
Applications for MTI
- Multichannel stability analysis – The TDC can measure the stability of multiple sources against a user-supplied reference. The Web-UI automatically generates ADEV stability plots. Reference and channel can be at any frequency within the specified operation range of the MTI. Up to four sources can be measured and plotted at the same time.
- Time delay measurement–The travel time (delay) of signals is susceptible to environmental effects. Often, the range of the time delay over operating conditions is a specification that must be confirmed by direct measurement. The MTI can provide a cost-effective method of accurately measuring delay on multiple channels.
- Time event logging–The MTI time tags and logs each incoming event. When operating with a PTP grandmaster, the arrival time of events is referenced to PTP time source. With internal storage for 1 million events per channel, the MTI can be an effective event logger.
- Distributed event correlation–For distributed facilities, it is often necessary to measure event times at multiple locations. For accurate timing, the units must be synchronized.
Highlights of MTI
- Multichannel event time logging referenced to PTPv2 Master timebase
- Dedicated TDC on all inputs for high-precision delay measurement between channels
- Deep buffer of event for logging capability over extended period
- Integrated GUI for monitoring and data analysis
- Data available by file download (hdf5) or Ethernet (TCP/IP sockets)
- Python Script is provided to streamline data acquisition
- Adjustable input characteristics such as edge type and threshold voltage