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: http://www.sai.msu.su/~er/xntp/driver26.html
Дата изменения: Unknown Дата индексирования: Sat Dec 22 01:53:41 2007 Кодировка: Поисковые слова: transit |
Address: 127.127.26.u
Reference ID: GPS
Driver ID: GPS-HP
Serial Port: /dev/hpgpsu
; 9600 baud, 8-bits,
no parity
Features: none
This driver supports the HP 58503A Time and Frequency Reference Receiver. It uses HP SmartClock (TM) to implement an Enhanced GPS receiver. The receiver accuracy when locked to GPS in normal operation is better than 1 usec. The accuracy when operating in holdover is typically better than 10 us per day. It receiver should be operated with factory default settings. Initial driver operation: expects the receiver to be already locked to GPS, configured and able to output timecode format 2 messages.
The driver uses the poll sequence The driver processes the response at the <cr> and <lf> The T is the on-time character, at 980 msec. before the next 1PPS
edge. The # is the timecode format type. We look for format 2. Without
any of the CLK or PPS stuff, then, the receiver buffer timestamp at the
This receiver also provides a 1-PPS signal, but I haven't figured out
how to deal with any of the CLK or PPS stuff yet. Stay tuned.
When enabled by the :PTIME:TCODE?
to get a
response from the receiver. The receiver responds with a timecode string
of ASCII printing characters, followed by a
T#yyyymmddhhmmssMFLRVcc<cr><lf>
T#yyyymmddhhmmssMFLRVcc<cr><lf>
Monitor Data
flag4
fudge flag, every received
timecode is written as-is to the clockstats
file.
Fudge Factors
time1 time
time2 time
stratum number
refid string
GPS
.
flag1 0 | 1
flag2 0 | 1
flag3 0 | 1
flag4 0 | 1
clockstats
recording if set.
David L. Mills (mills@udel.edu)