Table 3. LED Descriptions (Continued)
Pin Description Color Indication
REF Indicates the status of the
reference signal.
Off There is no reference signal, or
the device is not locked to the
reference signal.
Green Blinking—The device is not
locked to the reference signal.
Solid—The device is locked to
the reference signal.
PPS Indicates the pulse per
second (PPS).
Off There is no reference signal, or
the device is not locked to the
reference signal.
Green Blinking—The device is not
locked to the reference signal.
Solid—The device is locked to
the reference signal.
GPS Indicates whether the
GPSDO is locked.
Off There is no GPSDO, or the
device or the GPS is not locked.
Green The GPSDO is locked.
LINK Indicates the status of the
link to a host computer.
Off There is no link to a host
computer.
Green/
Yellow/Re
d
The host is actively
communicating with the device.
RF 1 TX1
RX1
Indicates the transmit
status of the device.
Off The device is not active.
Red The device is receiving data.
Green The device is transmitting data.
RX2 Indicates the receive status
of the device.
Off The device is not receiving data.
Green The device is receiving data.
USRP-2950/2952/2953/2954/2955 Getting Started Guide | © National Instruments | 17