From 4ded1c1fa0bc21c61f91a2dbe864835986745121 Mon Sep 17 00:00:00 2001 From: roberto Date: Sun, 17 Aug 2008 17:37:33 +0000 Subject: Flatten the dist and various 4.n.n trees in preparation of future ntp imports. --- html/driver19.htm | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 html/driver19.htm (limited to 'html/driver19.htm') diff --git a/html/driver19.htm b/html/driver19.htm new file mode 100644 index 0000000..a5cd5e0 --- /dev/null +++ b/html/driver19.htm @@ -0,0 +1,124 @@ + + + + + Heath WWV/WWVH Receiver + + + + +

+Heath WWV/WWVH Receiver

+ +
+

+Synopsis

+Address: 127.127.19.u +
Reference ID: WWV +
Driver ID: WWV_HEATH +
Serial Port: /dev/heathu; 1200 baud, 8-bits, no parity +
Features: tty_clk +
Requires: /usr/include/sys/termios.h header file with modem +control +

+Description

+This driver supports the Heath GC-1000 Most Accurate Clock, with RS232C +Output Accessory. This is a WWV/WWVH receiver somewhat less robust than +other supported receivers. Its claimed accuracy is 100 ms when actually +synchronized to the broadcast signal, but this doesn't happen even most +of the time, due to propagation conditions, ambient noise sources, etc. +When not synchronized, the accuracy is at the whim of the internal clock +oscillator, which can wander into the sunset without warning. Since the +indicated precision is 100 ms, expect a host synchronized only to this +thing to wander to and fro, occasionally being rudely stepped when the +offset exceeds the default CLOCK_MAX of 128 ms. + +

The internal DIPswitches should be set to operate at 1200 baud in MANUAL +mode and the current year. The external DIPswitches should be set to GMT +and 24-hour format. It is very important that the year be set correctly +in the DIPswitches; otherwise, the day of year will be incorrect after +28 April of a normal or leap year. + +

In MANUAL mode the clock responds to a rising edge of the request to +send (RTS) modem control line by sending the timecode. Therefore, it is +necessary that the operating system implement the TIOCMBIC and +TIOCMBIS ioctl system calls and TIOCM_RTS control bit. +Present restrictions require the use of a POSIX-compatible programming +interface, although other interfaces may work as well. + +

The clock message consists of 23 ASCII printing characters in the following +format: +

hh:mm:ss.f     dd/mm/yr<cr>
+
+hh:mm:ss.f = hours, minutes, seconds
+f = deciseconds ('?' when out of spec)
+dd/mm/yr = day, month, year
+The alarm condition is indicated by '?', rather than a digit, at A. Note +that 0?:??:??.? is displayed before synchronization is first established +and hh:mm:ss.? once synchronization is established and then lost again +for about a day. + +

A fudge time1 value of .07 s appears to center the clock offset residuals. +

+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 WWV.
+ +
+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
+
+Additional Information + +

Reference Clock Drivers  +

+
+David L. Mills (mills@udel.edu)
+ + + -- cgit v1.1