= JJY Receivers
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== Synopsis

["verse",subs="normal"]
Name: jjy
Reference ID: JJY
Serial Port: +/dev/jjyu+; See corresponding receiver

== Warning

Some modes of this driver report only two-digit years, and are thus
reliant on the system clock to be near correct before samples will be
processed properly. You will not be able to use them to run
autonomously, nor will it reliably recover from a trashed or zeroed
system clock.

== Description

This driver supports the following the JJY receivers and the GPS clock
sold in Japan, and the time service through a telephone line.

[width="100%",cols="<50%,<50%",]
|=================================================
|link:#subtype-1[Tristate Ltd.   TS-JJY01, TS-JJY02] |link:#subtype-6[SEIKO TIME SYSTEMS INC.   TDC-300]
|link:#subtype-2[C-DEX Co.,Ltd.   JST2000]           |link:#subtype-100[Telephone JJY]
|link:#subtype-3[Echo Keisokuki Co.,Ltd.   LT-2000]  |
|link:#subtype-4[CITIZEN T.I.C. CO.,LTD.   JJY-200]  |
|link:#subtype-5[Tristate Ltd.   TS-GPSclock-01]     |
|=================================================

* [[subtype-1]]Tristate Ltd.   TS-JJY01, TS-JJY02 https://www.tristate.ne.jp/ (Japanese only)
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _1_ `time1` _0.NNN_ `flag1 {0 | 1}`;;
  `time1` may specify a constant to be added to the time offset for the
  time from the receiver, a fixed-point decimal number in seconds. You
  may specify the time offset from several tens of milliseconds (0.0NN
  seconds) to a hundred and several tens of milliseconds (0.1NN seconds)
  for this clock. +
  `flag1` has no effect for time synchronization. When `flag1` is set to
  1, status commands are issued before `DATE` and `STIM` commands, and
  write a response text into the `clockstats` file.
+
[width="100%",cols="<50%,<50%",]
|====================================
|0 (Default) | `DCST` and `STUS` commands are not issued
|1           | `DCST` and `STUS` commands are issued
|====================================
--
+
Interface::
RS-232C, 9600 bps, 8-bits, no parity, 1 stop bit;;

Time code format::
+
[width="100%",cols="<25%,<10%,<65%",]
|==================================================
|Command       | -\-> |Reply
|`dcst{CR}{LF}`| -\-> |`valid{CR}{LF} \| invalid{CR}{LF}`
|`stus{CR}{LF}`| -\-> |`adjusted{CR}{LF} \| unadjusted{CR}{LF}`
|`time{CR}{LF}`| -\-> |`HH:MM:SS{CR}{LF}`
|`date{CR}{LF}`| -\-> |`YYYY/MM/DD WWW{CR}{LF}`
|`stim{CR}{LF}`| -\-> |`HH:MM:SS{CR}{LF}`
|==================================================
+
The date and time are requested separately. The time is requested
before and after the date request to check uncertainty of the date
whether it's before or after midnight.

* [[subtype-2]]C-DEX Co.,Ltd. JST2000 http://www.c-dex.co.jp/ (Japanese only)
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _2_ `time1` _0.NNN_;;
--
+
Interface::
RS-232C, 9600 bps, 8-bits, no parity, 1 stop bit;;

Time code format::
+
[width="100%",cols="<25%,<10%,<65%",]
|==================================================
|Command       | -\-> |Reply
|`{ENQ}1J{ETX}`| -\-> |`{STX}JYYMMDDWHHMMSSS{ETX}`
|==================================================
+
* [[subtype-3]]Echo Keisokuki Co.,Ltd. LT-2000
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _3_ `time1` _0.NNN_;;
--
+
Interface::
RS-232C, 9600 bps, 8-bits, no parity, 1 stop bit;;

Time code format::
+
[width="100%",cols="<25%,<10%,<65%",]
|==================================================
|Command                         | -\-> |Reply
|C                               | -\-> | (Subtype 2: Continuous)
|(Every second before 0.5 second)|      | `YYMMDDWHHMMSS{ST1}{ST2}{ST3}{ST4}{CR}`
|#                               | -\-> | (Subtype 1: Request & Send)
|==================================================
+
Note: Echo Keisokuki has been dissolved. Some business of the company was taken over by FreqTime Co., Ltd. in July, 2015.

* [[subtype-4]]CITIZEN T.I.C. CO.,LTD. JJY-200 http://www.tic-citizen.co.jp/ (Japanese only)
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _4_ `time1` _0.NNN_;;
--
+
Interface::
RS-232C, 4800 bps, 8-bits, no parity, 1 stop bit;;

Time code format::
+
[width="100%",cols="<25%,<10%,<65%",]
|==================================================
|Command       | -\-> |Reply
|(Every second)| -\-> |`XX YY/MM/DD W HH:MM:SS{CR}`
|==================================================
+
* [[subtype-5]]Tristate Ltd. TS-GPSclock-01 https://www.tristate.ne.jp/ (Japanese only)
+
This driver supports the Tristate TS-GPSclock-01 in command/response
subtype, though it is a GPS clock, not JJY radio clock. Using the
menus and the onboard switches, the TS-GPSclock-01 should be set to
command/response mode and JUST time zone.
+
Besides this driver, link:driver_nmea.html[the generic NMEA
GPS driver] supports the TS-GPSclock-01 in NMEA mode.
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _5_ `time1` _0.NNN_ `flag1 {0 | 1}`;;
  `time1` may specify a constant to be added to the time offset for the
  time from the receiver, a fixed-point decimal number in seconds. +
  `flag1` has no effect for time synchronization. When a `flag1` is set to
  1, status command is issued before `DATE` and `TIME` commands, and write
  a response text into a `clockstats` file.
+
[width="100%",cols="<50%,<50%",]
|=========================
|0 (Default)|`STUS` command is not issued
|1          |`STUS` command is issued
|=========================
--
+
Interface::
USB (/dev/ttyACM_0_);;

Time code format::
+
[width="100%",cols="<25%,<10%,<65%",]
|==================================================
|Command       | -\-> |Reply
|`stus{CR}{LF}`| -\-> |`*R{CR}{LF} \| *G{CR}{LF} \| *U{CR}{LF} \| +U{CR}{LF}`
|`time{CR}{LF}`| -\-> |`HH:MM:SS{CR}{LF}`
|`date{CR}{LF}`| -\-> |`YYYY/MM/DD{CR}{LF}`
|`time{CR}{LF}`| -\-> |`HH:MM:SS{CR}{LF}`
|==================================================
+
The date and time are requested separately. The time is requested
before and after the date request to check uncertainty of the date
whether it's before or after midnight.

* [[subtype-6]]SEIKO TIME SYSTEMS INC. TDC-300 https://www.seiko-sts.co.jp/ (English and Japanese)
+
The TDC-300 must be set to the type 3 data format using the front panel
menu display and the switches.
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _6_ `time1` _0.NNN_;;
--
+
Interface::
RS-232C, 2400 bps, 8-bits, no parity, 1 stop bit;;

Time code format::
+
[width="100%",cols="<25%,<10%,<65%",]
|==================================================
|Command                      | -\-> |Reply
|                             | -\-> |`{STX}YYMMDDWHHMMSS{ETX}`
|(5 to 10 mSec. before second)| -\-> |`{STX}{xE5}{ETX}`
|==================================================
+
* [[subtype-100]]Telephone JJY http://jjy.nict.go.jp/ (English and Japanese)
+
The telephone JJY is the time service through a public telephone line. +
The service is provided by the National Institute of Information and
Communications Technology in Japan.
+
ATTENTION; This subtype, the telephone JJY, can not be used with the
refclock_modem driver at the same time. Because the `phone`
statement in the configuration file is not involved with the
`server` statement, so the both the refclock_modem and this
refclock_jjy (subtype 100 to 180) can not recognize the
appropriate `phone` statement among the `phone` statements.
+
NTP configuration ({ntpconf})::
+
--
`refclock` _jjy_ `unit` _X_ `subtype` _(100, 101 to 180)_ `minpoll` _N (N >= 8)_;;
    The subtype 100 is specified, this driver does not issue the loopback
    command in order to measure the delay, and the delay of the
    telephone line and the system processing is not adjusted.
+
The subtype 101 to 180 is specified, this driver issues the loopback
command and measures the delay of the telephone line and the system
processing through the Telephone JJY loopback circuit.
+
The round trip time through the Telephone JJY loopback circuit is
measured 5 times, and each delay time is greater than 700
milliseconds, that delay time is ignored during average delay time
calculation. Also, if the valid delay time (<= 700 ms) is
measured more than 3 times, the maximum delay time among the valid
delay times is ignored, and if the valid delay time is measured more
than 4 times, the minimum delay time among them is ignored, like
marking/grading sports judgment.
+
The adjustment time is calculated by the formula, multiply (the
measured round trip time) by ((the subtype number) - 100) %,
and the adjustment delay time is added to the synchronizing time.
+
If you choose the automatic delay adjustment, in other words, the subtype
101 to 180 is specified, the recommended subtype number is 145 to 165.
+
The default polling interval 6 (64 seconds) is too short for this
subtype. The `minpoll` should be set to greater than or equal to 8 (256
seconds, about 4 minutes).
+
The interval time is given the value in second power of 2. The
minpoll value 12 is 4096 seconds interval (about 1 hour), 14 is
16384 seconds interval (about 4.5 hours), 16 is 65536 seconds (about
18 hours), respectively.

`flag1 {0 | 1}` `flag2` _{0|1}_ `flag3` _{0|1}_ `flag4` _{0|1}_;;
    `time1` may specify a constant to be added to the time offset for
    the time from the receiver, a fixed-point decimal number in
    seconds.  When the subtype 100 is specified, the `time1` may be
    specified in order to adjust the time offset.  When the subtype 101
    to 180 is specified, the `time1` should not be specified because
    this driver adds some percentage of the measured loopback delay,
    depending on the value of the subtype number.
+
.Flag1 is the modem dialing type
[width="100%",cols="<34%,<33%,<33%",]
|=================================
|0 (Default)|Tone |`ATDWTnn...nn`
|1          |Pulse|`ATDWPnn...nn`
|=================================
+
.Flag2 is the modem error correction type.
[width="100%",cols="<34%,<33%,<33%",]
|=======================================
|0 (Default)|Normal               |`AT\N0`
|1          |Auto V42, MNP, Normal|`AT\N3`
|=======================================
+
.Flag3 is the modem speaker switch.
[width="100%",cols="<34%,<33%,<33%",]
|=======================================
|0 (Default)|Off         |`ATM0Ln`
|1          |On          |`ATM2Ln`
|=======================================
+
.Flag4 is the modem speaker volume.
[width="100%",cols="<34%,<33%,<33%",]
|=======================================
|0 (Default) |Low    |`ATMnL1`
|1           |Middle |`ATMnL2`
|=======================================

`phone` _042NNNNNNN_;;
   The phone number is available at http://jjy.nict.go.jp/time/teljjy (Japanese and English) +
   The number of digits of the phone number is checked. If the
   international access number and the country number are added in
   order to call from outside of Japan, the number of digits is over
   the limit.
+
The first 2 or 3 digits are checked. The emergency service number
and the special service number in Japan are not allowed.
+
Calling from extension line, the number for an outside line should
be prefix "0," (Zero, Comma). The prefix is also checked, and no
other outside access number is allowed.
--
+
Interface::
RS-232C or USB, 2400 bps, 8-bits, no parity, 1 stop bit;;
Modem control commands:;;

+ATE0Q0V1, ATMnLn, AT&K4, AT+MS=V22B, AT%C0, AT\Nn, ATH1, ATDWxnn...nn `+++`, ATH0+;;

Time code format::
+
[width="100%",cols="<15%,<10%,<15%,<10%,<50%",]
|==================================================
|Prompt         | -\-> |Command      | -\-> |Reply
|`Name{SP}?{SP}`| -\-> |`TJJY{CR}`   | -\-> |Welcome messages
|>              | -\-> |`LOOP{CR}`   | -\-> |(Switch to the loopback circuit)
|               | -\-> |(One char.)  | -\-> |(One char.)
|  	   	        | -\-> |`COM{CR}`    | -\-> |(Exit from the loopback circuit)
|>              | -\-> |`TIME{CR}`   | -\-> |`HHMMSS{CR}HHMMSS{CR}HHMMSS{CR}` 3 times on second
|>              | -\-> |`4DATE{CR}`  | -\-> |`YYYYMMDD{CR}`
|>              | -\-> |`LEAPSEC{CR}`| -\-> |`{SP}0{CR}` \| `+1{CR}` \| `-1{CR}`
|>              | -\-> |`TIME{CR}` 	 | -\-> |`HHMMSS{CR}HHMMSS{CR}HHMMSS{CR}` 3 times on second
|>              | -\-> |`BYE{CR}` 	 | -\-> |Sayounara messages
|==================================================
+
The date and time are requested separately. The time is requested
before and after the date request to check uncertainty of the date
whether it's before or after midnight.
+
The leap second is not handled, and only written in the clockstats
file as information.


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

The user is expected to provide a symbolic link to an available serial
port device:

----------------------------------------------------------------
ln -s /dev/ttyS0 /dev/jjy0
----------------------------------------------------------------

Using an RS-232C to USB converter cable, the clock or a modem can be
connected to a USB port instead of a serial port with this symbolic
link:

----------------------------------------------------------------
ln -s /dev/ttyUSB0 /dev/jjy0
----------------------------------------------------------------

== Monitor Data

The driver writes sent and received data to/from the JJY receivers, GPS
clock, and the modem into the +clockstats+ file.

[subs="normal"]
----------------------------------------------------------------
statsdir /var/log/ntpd/
filegen clockstats file clockstats type day enable
----------------------------------------------------------------

.Mark of the clockstats record
[width="100%",cols="<50%,<50%",]
|============================================================
|+JJY+ | Information message (This refclock starts or stops.)
|+-->+ | Sent data
|+<--+ | Received data
|+---+ | Information message
|+===+ | Information message (Start of each polling, and sync. time.)
|+-W-+ | Warning message
|+-X-+ | Error message
|============================================================

== Driver Options

+unit+ 'number'::
  The driver unit number, defaulting to 0. Used as a distinguishing
  suffix in the driver device name.
+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}+::
  See corresponding receiver.
+flag2 {0 | 1}+::
  See corresponding receiver.
+flag3 {0 | 1}+::
  See corresponding receiver.
+flag4 {0 | 1}+::
  See corresponding receiver.
+subtype+::
   Used to select a device type and serial parameters.
+mode+::
  Synonym for subtype, retained for backward compatibility.
+path+ 'filename'::
  Not used by this driver.
+ppspath+ 'filename'::
  Not used by this driver.
+baud+ 'number'::
  Not used by this driver. The subtype implies the baud rate.

== Configuration Examples

See the examples in the Description section.

'''''

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