JJY Receivers

Synopsis

Description

This driver supports the following JJY receivers sold in Japan.

• Tristate Ltd. JJY01 http://www.tristate.ne.jp/ (Japanese only)
  

  Time code format

  
  

  Command		Reply
  date<CR><LF>		YYYY/MM/DD WWW<CR><LF>
  stim<CR><LF>		HH:MM:SS<CR><LF>

  
  

  NTP configuration ( ntp.conf )

  server   127.127.40.X   mode 1

  
  

• C-DEX Co.,Ltd. JST2000 http://www.c-dex.co.jp/ (Japanese only)
  

  Time code format

  
  

  Command		Reply
  <ENQ>1J<ETX>		<STX>JYYMMDD HHMMSSS<ETX>

  
  

  NTP configuration ( ntp.conf )

  server   127.127.40.X   mode 2

  
  

• Echo Keisokuki Co.,Ltd. LT-2000 http://www.clock.co.jp/ (Japanese only)

  Time code format

  
  

  Command		Reply
  C		( Mode 2 : Continuous )
  		YYMMDDWHHMMSS<ST1><ST2><ST3><ST4><CR>
  #		( Mode 1 : Request&Send )

  
  

  NTP configuration ( ntp.conf )

  server   127.127.40.X   mode 3

JJY is the radio station which transmites the JST (Japan Standard Time) in long wave radio. The station JJY is operated by the National Institute of Information and Communications Technology. An operating announcement and some information are avaiable from http://www.nict.go.jp/ (English and Japanese) and http://jjy.nict.go.jp/ (English and Japanese)

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/jjy0

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

Monitor Data

The driver writes each timecode as received to the clockstats file.

Fudge Factors

time1 time

Specifies the time offset calibration factor, in seconds and fraction, with default 0.0.

time2 time

Not used by this driver.

stratum number

Specifies the driver stratum, in decimal from 0 to 15, with default 0.

refid string

Specifies the driver reference identifier, an ASCII string from one to four characters, with default JJY.

flag1 0 | 1

Not used by this driver.

flag2 0 | 1

Not used by this driver.

flag3 0 | 1

Not used by this driver.

flag4 0 | 1

Not used by this driver.