6.1.4. Configuring Garmin Refclocks

6.1.4.1. General Notes

The Garmin GPS18-LVC works well with NTP. Beware: The other models of the GPS18 don't have PPS support. You should be able to get one for under $100.

It comes with bare wires. You need to supply 5V and wire it up to a DB-9 connector.

You can get the 5V from a USB connector.

You can also get 5V from some serial cards. (The context is powering things like bar code scanners.) The SIIG CyberSerial 4S has jumpers to supply 5V or 12V on pin 9/RI.

Please note that the GPS18x LVC sometimes gives odd huge offsets in the range of -600ms upto -700ms.

6.1.4.2. Related Links

• http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm
• http://time.qnan.org

Related Topics: GarminRefclockUsers