__________________________________________________________________________ 2 Connectors
PolaRx3e Product Family Hardware Manual v1.1.0
7
2
Connectors
2.1
Rear Panel
Depending on your particular receiver model, the rear panel features four or five connectors.
PolaRx3e and PolaRx3eG
PolaRx3eTR
2.1.1
MAIN (TNC)
Connect an active GNSS antenna to this connector. The gain at the connector (antenna gain minus
cable losses) must be in the range 15 to 50dB.
By default, the MAIN connector provides a 5V DC supply to feed the antenna. Other voltages can be
imposed through pin ANT_EXT of the I/O connector on the front panel (see section 2.2.4). The
maximum current is 200mA.
2.1.2
PPS OUT (BNC)
xPPS output (3.3V CMOS). The characteristics of the xPPS output signal are specified by the
setPPSParameters
command.
2.1.3
REF IN (BNC)
Use this connector to provide the receiver with an external 10 MHz frequency reference, to be used
instead of the internal oscillator. The reference signal must be sinusoidal with a peak-to-peak
amplitude (unloaded) ranging from 0.5V to 2V (-8dBm to +4dBm in a 50
load).
Connecting or disconnecting the external 10 MHz reference must be done with the receiver switched
off. The receiver checks the presence of the external frequency reference during its start-up phase. If
a valid reference signal is found, the receiver clock is automatically locked to this reference.
Otherwise the internal oscillator is used as frequency reference.
If a 10 MHz reference is connected while the receiver is already operating, it will be ignored. If the 10
MHz reference is removed during operation, the receiver will stop.
2.1.4
PPS IN (BNC)
Time synchronization input (input level 3.3V CMOS with 4.7k
pull down resistor, 5V tolerant,
V
IH
>2.3V, V
IL
<1V), to be connected to a one pulse-per-second external reference.
