" graphics="on"}% See ConfiguringMotorolaOncoreRefclocksDev for discussion of this topic.
6.1.11. Configuring Motorola ONCORE Refclocks
I try to summarize the necessary steps to set up an M12+T for precision timing using:
- Set Position-Hold position, either:
- Manually: If the Antenna position is known the user can specify the coordinates by the @@As command.
- Using Autosurvey: The mode 3 in @@Gd command will automatically average 10,000 position fixes and then force the receiver into Postion-Hold. This operation can take some hours. To check if the receiver is in Position-Hold mode, the bit 4 ("AutoSurvey Mode" of the @@Ha or @@Hb command has to be set 00, during averaging has value 01).
- Set Cable delay with command @@Az: In our case the a cable of 5 meters means a delay of 25ns. After sending this command we guess the time included in the @@Hb answer is time automatic corrected of cable delay.
- Set the Timing Parameters by the commands:
- @@Gf: This message is used to set the T-RAIM alarm limit (between 300 and 1,000,000ns).
- @@Ge: This message is used to turn the T-RAIM function on.
- @@Hn: The @@Hn T-RAIM Status Message to get status strings that alert to any alarm conditions.
Richard Gilbert says:
Assuming that your version of NTP was built with
the ONCORE refclock driver, you should be able to connect your Motorola
Oncore GT+ to a serial port and configure it as directed by the
documentation for that version!
I've only configured an Oncore on ntpd 4.2.0 which requires two links:
pointing to your serial port.
Next you need
which is configuration file that looks something like this:
# Reference Clock configuration for Motorola Oncore M12
# Five Choices for MODE
# (0) ONCORE is preinitialized, don't do anything to change it.
# nb, DON'T set 0D mode, DON'T set Delay, position...
# (1) NO RESET, Read Position, delays from data file, lock it in, go to 0D mode.
# (2) NO RESET, Read Delays from data file, do SITE SURVEY to get position,
# lock this in, go to 0D mode.
# (3) HARD RESET, Read Position, delays from data file, lock it in, go to 0D mode.
# (4) HARD RESET, Read Delays from data file, do SITE SURVEY to get position,
# NB. If a POSITION is specified in the config file with mode=(2,4)
# then this position is set as the INITIAL position of the ONCORE.
# This can reduce the time to first fix.
LAT 39 45.3753 # Positive is North.
LONG -75 04.27187 # Negative is West
HTGPS 18.28 M # Height in meters.
TRAIM YES # May need this if antenna position is suboptimal.
Finally, you need to add a server statement in
# Reference Clock (Motorola Oncore M12)
server 127.127.30.0 prefer
All this stuff is, AFAIK, version specific.
What I have shown here is working on a Sun Ultra 10 running Solaris 8.
Your mileage may vary.
Also see: MotorolaOncoreRefclockUsers