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diff --git a/usr.sbin/ntp/doc/ntp_clock.8 b/usr.sbin/ntp/doc/ntp_clock.8 deleted file mode 100644 index 7a3b43b..0000000 --- a/usr.sbin/ntp/doc/ntp_clock.8 +++ /dev/null @@ -1,302 +0,0 @@ -.\" -.\" $FreeBSD$ -.\" -.Dd January 12, 2000 -.Dt NTP_CLOCK 8 -.Os -.Sh NAME -.Nm ntp_clock -.Nd NTP daemon clock options -.Sh SYNOPSIS -.Pa /etc/ntp.conf -.Sh DESCRIPTION -The NTP Version 4 daemon supports many different radio, -satellite and modem reference clocks -plus a special pseudo-clock used for backup -or when no other clock source is available. -Detailed descriptions of individual device drivers -and options can be found in the -.Qo -Reference Clock Drivers -.Qc -page -(available as part of the HTML documentation -provided in -.Pa /usr/share/doc/ntp ) . -Additional information can be found in the pages referenced there, -including the -.Qo -Debugging Hints for Reference Clock Drivers -.Qc -and -.Qo -How To Write a Reference Clock Driver -.Qc -pages. -In many drivers, -support for a PPS signal is available as described in the -.Qo -Pulse-per-second (PPS) Signal Interfacing -.Qc -page. -Many drivers support special line discipline/streams modules -which can significantly improve the accuracy using the driver. -These are described in the -.Qo -Line Disciplines and Streams Drivers -.Qc -page. -.Pp -A reference clock will generally (though not always) -be a radio timecode receiver -which is synchronized to a source of standard time -such as the services offered by the NRC in Canada -and NIST and USNO in the United States. -The interface between the computer and the timecode receiver -is device dependent, but is usually a serial port. -A device driver specific to each reference clock -must be selected and compiled in the distribution; -however, most common radio, satellite and modem clocks -are included by default. -Note that an attempt to configure a reference clock -when the driver has not been included -or the hardware port has not been appropriately configured -results in a scalding remark to the system log file, -but is not otherwise hazardous. -.Pp -For the purposes of configuration, -.Xr ntpd 8 -treats reference clocks in a manner -analogous to normal NTP peers as much as possible. -Reference clocks are identified by a syntactically correct -but invalid IP address, -in order to distinguish them from normal NTP peers. -Reference clock addresses are of the form 127.127.t.u, -where -.Ar t -is an integer denoting the clock type and -.Ar u -indicates the unit number. -While it may seem overkill, -it is in fact sometimes useful -to configure multiple reference clocks of the same type, -in which case the unit numbers must be unique. -.Pp -The -.Ic server -command is used to configure a reference clock, -where the address argument in that command is the clock address. -The key, -version and ttl options are not used for reference clock support. -The mode option is added for reference clock support, -as described below. -The prefer option can be useful -to persuade the server to cherish a reference clock -with somewhat more enthusiasm than other reference clocks or peers. -Further information on this option can be found in the -.Qo -Mitigation Rules and the prefer Keyword -.Qc -page. -The minpoll and maxpoll options have meaning -only for selected clock drivers. -See the individual clock driver document pages -for additional information. -.Pp -The stratum number of a reference clock is by default zero. -Since the -.Xr ntpd 8 -daemon adds one to the stratum of each peer, -a primary server ordinarily displays stratum one. -In order to provide engineered backups, -it is often useful to specify the reference clock stratum -as greater than zero. -The stratum option is used for this purpose. -Also, in cases involving both a reference clock -and a pulse-per-second (PPS) discipline signal, -it is useful to specify the reference clock identifier -as other than the default, depending on the driver. -The refid option is used for this purpose. -Except where noted, -these options apply to all clock drivers. -.Ss Reference Clock Commands -.Bl -tag -width indent -.It Xo Ic server No 127.127. Ns Xo -.Ar t Ns No . Ns Xo -.Ar u -.Op prefer -.Op mode Ar int -.Op minpoll Ar int -.Op maxpoll Ar int -.Xc -.Xc -.Xc -This command can be used to configure reference clocks -in special ways. -The options are interpreted as follows: -.Bl -tag -width indent -.It prefer -Marks the reference clock as preferred. -All other things being equal, -this host will be chosen for synchronization -among a set of correctly operating hosts. -See the -.Qo -Mitigation Rules and the prefer Keyword -.Qc -page -for further information. -.It mode Ar int -Specifies a mode number -which is interpreted in a device-specific fashion. -For instance, it selects a dialing protocol in the ACTS driver -and a device subtype in the parse drivers. -.It minpoll Ar int -.It maxpoll Ar int -These options specify the minimum and maximum polling interval -for reference clock messages, in seconds to the power of two. -For most directly connected reference clocks, -both minpoll and maxpoll default to 6 (64 s). -For modem reference clocks, -minpoll defaults to 10 (17.1 m) -and maxpoll defaults to 14 (4.5 h). -The allowable range is 4 (16 s) to 17 (36.4 h) inclusive. -.El -.It Xo Ic fudge No 127.127. Ns Xo -.Ar t Ns No . Ns Xo -.Ar u -.Op time1 Ar sec -.Op time2 Ar sec -.Op stratum Ar int -.Op refid Ar string -.Op mode Ar int -.Op flag1 Ar 0 Ns | Ns Ar 1 -.Op flag2 Ar 0 Ns | Ns Ar 1 -.Op flag3 Ar 0 Ns | Ns Ar 1 -.Op flag4 Ar 0 Ns | Ns Ar 1 -.Xc -.Xc -.Xc -This command can be used to configure reference clocks -in special ways. -It must immediately follow the -.Ic server -command which configures the driver. -Note that the same capability is possible at run time -using the -.Xr ntpdc 8 -program. -The options are interpreted as follows: -.Bl -tag -width indent -.It time1 Ar sec -Specifies a constant to be added to the time offset produced -by the driver, a fixed-point decimal number in seconds. -This is used as a calibration constant -to adjust the nominal time offset of a particular clock -to agree with an external standard, -such as a precision PPS signal. -It also provides a way to correct a systematic error -or bias due to serial port latencies, -different cable lengths or receiver internal delay. -The specified offset is in addition to the propagation delay -provided by other means, such as internal DIPswitches. -Where a calibration for an individual system -and driver is available, -an approximate correction is noted -in the driver documentation pages. -.It time2 Ar secs -Specifies a fixed-point decimal number in seconds, -which is interpreted in a driver-dependent way. -See the descriptions of specific drivers in the -.Qo -Reference Clock Drivers -.Qc -page. -.It stratum Ar int -Specifies the stratum number assigned to the driver, -an integer between 0 and 15. -This number overrides the default stratum number -ordinarily assigned by the driver itself, usually zero. -.It refid Ar string -Specifies an ASCII string from one to four characters -which defines the reference identifier used by the driver. -This string overrides the default identifier -ordinarily assigned by the driver itself. -.It mode Ar int -Specifies a mode number which is interpreted -in a device-specific fashion. -For instance, -it selects a dialing protocol in the ACTS driver -and a device subtype in the parse drivers. -.It flag1 flag2 flag3 flag4 -These four flags are used for customizing the clock driver. -The interpretation of these values, -and whether they are used at all, -is a function of the particular clock driver. -However, by convention -flag4 is used to enable recording monitoring data -to the clockstats file configured with the -.Ic filegen -command. -When a PPS signal is available, -a special automatic calibration facility is provided. -If the flag1 switch is set -and the PPS signal is actively disciplining the system time, -the calibration value is automatically adjusted -to maintain a residual offset of zero. -Further information on the -.Ic filegen -command can be found in the -.Xr ntp_mon 8 -page. -.El -.It Ic pps device [assert|clear] [hardpps] -Specifies the name and options for the serial port device -to which the PPS signal is connected. -Note, this command replaces use of fudge flag3, -which was used for the same purpose in NTPv3. -Note that this command should preceed the -.Ic server -and -.Ic fudge -commands for the same device. -Note also that the assert, -clear and hardpps options are only available -if the ppsapi standard PPS interface is available. -.Bl -tag -width indent -.It device -Specify the device name associated with the PPS signal. -The name must match exactly the link name specified -in the driver documentation page. -.Ic assert -.Ic clear -Using assert or clear specifies -if the high going or low going edge -of the signal must be used. -The default is assert. -.Ic hardpps -This flag is used to tell the kernel that the signal -from this device must be used to drive hardpps(). -The assert, clear and hardpps options are only available -if the PPSAPI is used. -.El -.El -.Sh SEE ALSO -.Xr ntp_conf 8 , -.Xr ntpd 8 , -.Xr ntpdc 8 , -.Xr ntpq 8 -.Pp -In addition to the manual pages provided, -comprehensive documentation is available on the world wide web -at -.Li http://www.ntp.org/ . -A snapshot of this documentation is available in HTML format in -.Pa /usr/share/doc/ntp . -.Sh HISTORY -Written by -.An Dennis Ferguson -at the University of Toronto. -Text amended by -.An David Mills -at the University of Delaware. |
