Instructions

UM-0085-B09 DT80 Range User Manual Page 270
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Note: If the DT80 system time is synchronised to an NTP server (see below), and the DT80 time is set to local or local standard time,
then the
TIME_ZONE profile setting must be set correctly. If NTP is not used then this profile setting is not used.
Setting the Time in dEX
The dEX configuration builder can be used to set the DT80 time manually, or synchronise it to the PC's time. Select the
Logger menu, then Set logger date & time. This will display a dialog box showing the PC time and the logger time.
Figure 109: Time adjustment dialog in configuration builder
To correct the logger time so that it matches the PC time simply press the Set logger's time to match computer's time
button. Alternatively, select the manual option to set the logger's time to a specific value. This will be required if the
logger is set to a different time zone to the PC, for example.
Automatic Time Adjustment (NTP)
Network Time Protocol (NTP) allows devices on a TCP/IP network to synchronise their clock to an NTP server, which will
in turn be linked to a very accurate time reference.
If your DT80 has Internet access, or if you have access to an NTP server on your local network, then you can enable the
DT80's automatic time adjustment feature. The DT80 will then periodically (by default, hourly) contact the NTP server
and if necessary adjust its clock/calendar to match.
For small time adjustments (by default, up to 3 seconds) the DT80 will gradually adjust its time by speeding up or slowing
down its clock for a period of time. This avoids any sudden changes in time, and the time will never go backwards (which
could have caused complications when you came to interpret the logged data). This process is also referred to as
"slewing" the time.
For example, if the NTP server indicates that the DT80 time is 1.2 seconds fast then the DT80 clock will be slowed down
by 10% (by default). After 13.2 seconds (12.0s as measured by the DT80 clock) the required time adjustment of -1.2s will
have been made and the clock rate will be set back to normal.
If a larger time adjustment is required, the "gradual" method is impractical and the DT80 will do a "jump" adjustment,
where the time will change instantaneously (forward or backward). A message is logged to the event log (see Event Logs
(P276)) each time a time jump occurs (including manual time changes).
Using NTP
In order to use NTP, you first need to ensure that you have an accessible NTP server.
If the DT80 has access to the Internet then you can use the public NTP server at 0.datataker.pool.ntp.org.
Alternatively, a local NTP server may be available on the local area network to which the DT80 is connected. If this is the
case then you will need to find out the IP address or host name of the NTP server. Note that using a local server will
normally result in better time accuracy, because it avoids the variable delays that may occur when making a request over
the Internet.
Once you have determined the address of the NTP server that you wish to use, you can enable NTP updates by setting
the following profiles:
PROFILE LOCALE TIME_ZONE=offset
PROFILE NTP SERVER=host address
PROFILE NTP BACKGROUND_ENABLE=YES
The timezone setting (offset) is the time difference between UTC (GMT) time and the logger's local time. For example,
for Pacific Standard Time (UTC-8:00), use
PROFILE LOCALE TIME_ZONE=-8H
while for Australian Central Standard Time (UTC+9:30), use
PROFILE LOCALE TIME_ZONE=570M
(9.5 hours = 570 minutes)