I try to use gnss-sdr
these days with USRP B210.
When I connect GPS antenna with RX port,gnss-sdr
output well.But GPS antenna doesn't work when connect with GPS
port.
Does GPS port of USRP B210 only used for GPSDO?
Does GPS port of USRP B210 only used for GPSDO?
Yes. You can actually follow the RF trace on the board if you have it in front of you. Also, Ettus has their schematics online and you can see the connection there: The antenna port is connected to the antenna connector of the GPSDO alone.