User's Manual

4 P412 User’s Manual & Data Sheet
Figure 1: Notional UWB pulse in both time and frequency domain.
The P412 measures distance using a technique called Two Way Time of Flight. In this approach the
radio requesting the range measurement (the Requestor) will transmit a packet of pulses that will be
received by one or more units (the Responders). The responder will then measure the leading edge
of the waveform relative to the radio lock spot and transmit this information in a return (or
responding) packet. The Requestor will then measure the difference in phase between the transmitted
and received PN code and compensate this phase measurement by the leading edge measurement.
Dividing the result by two and multiplying by the speed of light yields a measurement of the distance
between the Requestor and Responder.
The user controls and monitors the P412 through a straight forward Application Programming
Interface (API) over USB, Serial or CAN connections. USB driver support is provided for Vista 32,
Vista 64, Win7 32 and Win7 64 operating systems. The API provides all the commands and
capabilities required by a user to design a network tailored for operating multiple P412s as ranging
radios. For details on the API see the following document:
• Ranging and Communications Module API Specification
For details on the USB and serial interfaces refer to
• USB and Serial Interfaces
To assist the user in demonstrating the performance of the P412 as a ranging radio, Time Domain also
provides a PC based Graphical User Interface (GUI). These GUI allows the user to exercise all of the
API commands and offers the following capabilities:
• They provide programmers with a visual example of a host application which interfaces to
the P412 through the API.
• They allow users to evaluate ranging and communications performance.
• They allow system analysts to visualize, collect and log raw ranging data such that it is
possible to develop algorithms/strategies tailored to a given application
Time Domain also provides sample C and Matlab for demonstrating the interface and performance of
the hardware.
For details on these GUIs refer to the following document:
• Ranging and Communications Module Reconfiguration and Evaluation Tool (RCM –
RET) User Guide