hopf GPS/DCF77 6021/komp for Serial Line

Last update: March 30, 2023 19:10 UTC (33276df3b)

Table of Contents


Address: 127.127.38.X

Reference ID: hopf (default), GPS, DCF

Driver ID: HOPF_S

Serial Port: /dev/hopfclockX

Serial I/O: 9600 baud, 8-bits, 1-stop, no parity



The refclock_hopf_serial driver supports hopf electronic receivers with serial Interface kompatibel 6021.

Additional software and information about the software driver is available from: http://www.atlsoft.de/ntp-tcp-netzwerkzeit/.

Latest NTP driver source, executables and documentation is maintained at: http://www.atlsoft.de/ntp-tcp-netzwerkzeit/.

Operating System Compatibility

The hopf clock driver has been tested on the following software and hardware platforms:

Platform Operating System
i386 (PC) Linux
i386 (PC) Windows NT
i386 (PC) Windows 2000

O/S Serial Port Configuration

The driver attempts to open the device /dev/hopfclockX where X is the NTP refclock unit number as defined by the LSB of the refclock address. Valid refclock unit numbers are 0 - 3.

The user is expected to provide a symbolic link to an available serial port device. This is typically performed by a command such as:

ln -s /dev/ttyS0 /dev/hopfclock0

Windows NT does not support symbolic links to device files. COMx is used by the driver, based on the refclock unit number, where unit 1 corresponds to COM1 and unit 3 corresponds to COM3.

Fudge Factors

time1 time

Specifies the time offset calibration factor, in seconds and fraction, with default 0.0. Should be set to 20 milliseconds to correct serial line and operating system delays incurred in capturing time stamps from the synchronous packets.

refid string

Specifies the driver reference identifier, GPS or DCF.

flag1 0 | 1

When set to 1, driver syncs even if only crystal driven.

Data Format

As specified in clock manual in section “Data String for NTP (Network Time Protocol)”.

Questions or Comments

Bernd Altmeier

Ing.-Büro für Software www.ATLSoft.de