Conference lassie::ucx

5332.0. "NTP and clock reset messages any Ideas...???" by PRIVAT::OTTO (getting better all the time) Wed Mar 12 1997 06:48

Hello,

A customer is running UCX 4.1 ECO2 on a AXP 1000 running OVMS 6.21h3.
They have an application that picks up the Time from a HOPF DCF77 Clock
Receiver connected to TTA0, every 10 minutes and set's the local time.

This system is setup as a Master-clock (what ever that really means)

sys$specific:[ucx$ntp]ucx$ntp.conf

;
; UCX$NTP.CONF
;
; (C) VCS Nachrichtentechnik GmbH. 1996
;
; 04-dec-1996   B. Gwosdz
; adapted for SN1SA2 as master-clock host
;
; 04-oct-1996   B. Gwosdz
;
;
master-clock 1
        
(from the manual 6.4.3.4 Configuring a Master Server)

Do I need to give this Master Server a Server statement as well ?

The customers problem is this:

This is the NTP Logfile on the Server System

sys$specific:[ucx$ntp]ucx$ntpd.log
* clock reset ~-27.949 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-10.627 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-22.733 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-5.391 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-30.361 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-11.039 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-30.828 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-23.276 sec by something, clearing.
* basetime: NTS offset is 794448000.000000
* clock reset ~-26.915 sec by something, clearing.



since there are no time stamps I assume that every 10 Minutes when the
application gets the Time from the DCF77 Clock Receiver
the local time will be set to the time that comes from the Radio Clock.
Am I right that the system uses the Hardware clock for 10 Minutes until 
the next "set time" from the Radio Clock comes ?
If so, then to me the logfile looks like the Hardware clock is 
very inaccurate on this AXP System.
Is this more a hardware related problem or does the NTP software needs to be "fixed"

Am I right ??
What else could be an explanation ??
If an IPMT is needed I will open one 

The manual is not clear/exhaustive about such an important topic.



Thanks for any helps/tips


OTTO

    Could they also be running another time service, such as DECnet/DTSS or
    DCE DTS, that is also trying to set the clock?
    
    -Tom

Hello Tom,

the do not run any other time service on this system 
(o DTSS etc).

I have instructed them to check what happens if they 
let the system run without external clock source 
for a few hours.
(let's see how the server logfile looks then )

Apart from that I don't see any errors , but who can tell
from the few pages in the manual anyway.



OTTO

Hi

the customer uses NTP from UCX 4.1 ECO2 to syncronize the time on two Alpha 
Systems (one is the server the other is the client getting the time).

This works fine as long as the Alpha that is the server is left running 
without a external time source.

The customer has a HOPF Radio Time Receiver connected to a serial Port on 
the "Time Server Alpha", they 
run a proccess/application that asks the Clock every 10 Minutes for the 
time and sets the system time.  When they run the appl to syncronize the time 
on the alpha to the external clock, they get clock reset messages 
in the UCX$NTPD.LOG file.


Now I wonder how an application that asks an external time source 
should act on the system time. If I am right NTP on VMS checks for the 
system Time and there are no "special" drivers or Line disciplines like in
xntpd for UNIX.

Are there any examples or recomendations on how such an application should 
be implemented ??




Thanks 

OTTO