National Instruments USRP-2940, Getting Started Manual

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Table 17. USRP-2945 Module Back Panel Connectors (Continued)
Connector Use
REF OUT Output terminal for an external reference signal for the LO on the device.
REF OUT is a female SMA connector with an impedance of 50 Ω, and it is
a single-ended reference output. The output signal at this connector is
10 MHz at 3.3 V.
REF IN Input terminal for an external reference signal for the LO on the device.
REF IN is a female SMA connector with an impedance of 50 Ω, and it is a
single-ended reference input. REF IN accepts a 10 MHz signal with a
minimum input power of 0 dBm (0.632 Vpk-pk) and a maximum input
power of 15 dBm (3.56 Vpk-pk) for a square wave or sine wave.
LO IN 0 IF2 Terminal for an external signal to the IF LO input on the RF 0
daughterboard. This signal can be used as the LO source for an RF 0
channel by selecting
external on that channel's LO source setting. LO IN 0
IF2 is a female SMA connector with an impedance of 50 Ω.
LO IN 0 IF1 Terminal for an external signal to the IF LO input on the RF 0
daughterboard. This signal can be used as the LO source for an RF 0
channel by selecting
external on that channel's LO source setting. LO IN 0
IF1 is a female SMA connector with an impedance of 50 Ω.
PCIe x4 Port for a PCI Express Generation 1, x4 bus connection through an MXI
Express four-lane cable.
LO IN 1 IF2 Terminal for an external signal to the IF LO input on the RF 0
daughterboard. This signal can be used as the LO source for an RF 0
channel by selecting
external on that channel's LO source setting. LO IN 1
IF2 is a female SMA connector with an impedance of 50 Ω.
LO IN 1 IF1 Terminal for an external signal to the IF LO input on the RF 0
daughterboard. This signal can be used as the LO source for an RF 0
channel by selecting
external on that channel's LO source setting. LO IN 1
IF1 is a female SMA connector with an impedance of 50 Ω.
PPS TRIG
OUT Output terminal for the pulse per second (PPS) timing reference. PPS TRIG
OUT is a female SMA connector with an impedance of 50 Ω, and it is a
single-ended input. The output signal is 0 V to 3.3 V TTL. You can also use
this port as triggered output (TRIG OUT) that you program with the PPS
Trig Out I/O signal.
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