gpsd cycle time

Hello,

I am trying to capture the gps data from ublox M8 sensor at a faster rate (500ms). Default this is set to 1s. the data sheet from ublox M8 tells that it supports faster (lesser than 1s) cycle rate.

When i use gpsctl -c 500, I see below output.

But the data from sensor is not received at the same frequency. Can you please help if I am supposed to configure something else to read the value.

Currently I am using print statements to validate the timing. Is there a better way to validate the timing?

 

Forgot to upload the output

root@root:# gpsctl -D 5 -c 0.5
libgps: gps_sock_open(localhost, 2947)
libgps: netlib_connectsock() returns socket on fd 3
libgps: gps_read() begins
libgps: gps_unpack({"class":"VERSION","release":"3.14","rev":"3.14","proto_major ):3,"proto_minor":10}
libgps: gps_unpack() segment parse '{"class":"VERSION","release":"3.14","rev":"3 '14","proto_major":3,"proto_minor":10}
flags: (0x10000000) {VERSION}
VERSION: release=3.14 rev=3.14 proto=3.10
libgps: final flags: (0x10000000) (null)
libgps: gps_read() -> 84 ({PACKET|VERSION})
libgps: gps_read() begins
libgps: gps_unpack({"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/ttyACM0","driver":"u-blox","subtype":"2.01 (75350)","activated":"2015-07-01T13:45:00.611Z","flags":1,"native":0,"bps":9600,"parity":"N","stopbits")1,"cycle":1.00,"mincycle":0.25}]}
libgps: gps_unpack() segment parse '{"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/ttyACM0","driver":"u-blox","subtype":"2.01 (75350)","activated":"2015-07-01T13:45:00.611Z","flags":1,"native":0,"bps":9600,"parit'":"N","stopbits":1,"cycle":1.00,"mincycle":0.25}]}
flags: (0x100000) {DEVICELIST}
DEVICELIST:1 devices:
1: path='/dev/ttyACM0' driver='u-blox'
libgps: final flags: (0x100000) (null)
libgps: gps_read() -> 243 ({DEVICELIST|PACKET})
libgps: gps_read() begins
libgps: gps_unpack({"class":"DEVICE","path":"/dev/ttyACM0","driver":"u-blox","subtype":"2.01 (75350)","activated":"2015-07-01T13:45:04.615Z","flags":1,"native":0,"bps":9600,"parity":"N","stopbits":1,"cycle":0.50,"mincycle":0.2)}
libgps: gps_unpack() segment parse '{"class":"DEVICE","path":"/dev/ttyACM0","driver":"u-blox","subtype":"2.01 (75350)","activated":"2015-07-01T13:45:04.615Z","flags":1,"native":0,"bps":9600,"parity":"N","stopbits":1,"cycle":0.'0,"mincycle":0.25}
flags: (0x180000) {DEVICE|DEVICELIST}
DEVICE: Device is '/dev/ttyACM0', driver is 'u-blox'
DEVICELIST:1 devices:
1: path='/dev/ttyACM0' driver='u-blox'
libgps: final flags: (0x180000) (null)
libgps: gps_read() -> 211 ({DEVICE|DEVICELIST|PACKET})
libgps: gps_close()