User's Manual

10 P412 User’s Manual & Data Sheet
4.1 Indicator Lights
The P412 is provided with two indicator LEDs mounted adjacent to the Digital Baseband FPGA. See
Figure 5 for exact locations.
The amber LED toggles at 1Hz to indicate that the FPGA has passed Built-In Test (BIT). If the
FPGA fails BIT, then the amber LED will blink at approximately 10 Hz. The green LED is initially
off indicating that the FPGA has not been loaded. It blinks rapidly to indicate that the FPGA has
been loaded and is getting a clock. After that, a steady on or off indicates a failure.
4.2 USB, Serial and CAN Interfaces
The P412 offers three different interfaces that allow users to control the module according to their
specific application needs. The standard interfaces supported by the system are: USB 2.0 through a
Micro-B USB connector, a 3.3V TTL-level serial interface and a CAN interface. The Serial and
CAN interfaces are physically connected to the board through a user supplied pigtail. The details of
the pigtail connection are shown in Figure 6.
Note the USB connection does not provide enough power to support the RCM.
The protocol used to communicate with the P412 is fully defined in the API Specification. Connection
to the Serial and USB interfaces are described in Time Domain application note Using the P4xx USB
and Serial Interfaces.
4.3 Antenna Ports
The P412 has two antenna ports, designated Port A and Port B. The connector used on each port is a
standard polarity female SMA connector (Digi-Key part number J801-ND). The two ports enable
single and dual antenna modes of operation.
An RF transfer switch on the P412 controls how the RF electronics are connected to the SMA
connector. Normal operation is either 1) Transmit/Receive on Port A or 2) Transmit of A, Receive on
B. Use of a transfer switch allows for future operational capability.
The P412 is intended to be used with the Broadspec antenna. Using any other antenna will require
FCC recertification. However, it is possible to add passive extension cables between the antenna port
and the antenna. Be aware that using alternate UWB antennas will likely change the RF time-of-
flight electrical distance between the antenna port and the phase center of the antenna. Failure to
account for such changes will result in an offset or bias error in range measurements. See the RCM
API Specification for details on how the electrical distance is defined and calibrated.