A8814 Acq
Page 24
System Options
Status
The system status page shows the current memory and flash disk utilization values, system up-time, and load
average. Also included on this page are two buttons for
Reboot
and
Shutdown
. It is important to use the
shutdown option prior to removing power from the AcquiSuite. The LCD console will report the reboot or
shutdown status.
Processes
The system process table is shown in both tree and tabular formats. The process list is useful when contacting
Obvius technical support.
Date and Time
The AcquiSuite keeps time using UTC or Universal time. All log files are recorded in UTC time as well.
Timestamps shown on the AcquiSuite local configuration pages are converted to local time for the convenience
of the installer. The date/time configuration page provides the following options
Date/time
in UTC and Local time.
Date/time
dropdown menus to select the current (Local) time manually.
Timezone
: a drop down list of the supported timezones.
Time sync protocol:
Select NTP or Rdate. Most Linux/Unix systems provide rdate, however many provide NTP as
well. Windows domain servers can also provide NTP. If possible use NTP as it is a more robust protocol.
Time Server:
Specify the dns name or ip address of your time server. The default “time.obvius.com” can be
used if the AcquiSuite has a connection to the Internet. The AcquiSuite will attempt to synchronize time with the
time server every time an upload session. This will ensure that the clock is checked and adjusted at a minimum
of once per day. Typically, the synchronization will align the clock to -1 second of the internet time
source or atomic clock. You may need to verify if your firewall will allow NTP or Rdate packets to pass through.
Generally, it is better to use a local time server if possible. The time server time.obvius.com supports both NTP
and Rdate time protocols. If you use a GSM connected system, you will probably need to use Rdate. NTP is
blocked by many cellular service carriers.
Universal Time Is Your Friend
Log data is stored in UTC time. This allows data collection services such as BMO to collect data from multiple
sites in different time zones. If you are operating your own database system to store log data from the
AcquiSuite, it is best to store the data in UTC time in the database as well, and only convert it to local time when
generating the final report or graph for the user.
If you store data in Local time, you will have the following issues.
1)
Local time is relative. Is Local the time where the AcquiSuite exists, or Local to where the data is stored. If
local to the AcquiSuite, you must shift each AcquiSuite data set depending on its location.
2)
There are about 11 time zones in the US. Some observe DST, others do not. These include Alaska, Aleutian,
Arizona, Central, Eastern, Hawaii, Indiana, Michigan, Mountain, Pacific, and Samoa.
3)
When converting to local time, there will be one hour of overlapping data in the fall when the time is
adjusted for Daylight Savings time. ie, log entries run 12:45, 1:00, 1:15, 1:30, 1:45, 1:00, 1:15, 1:30, 1:45,
2:00am. This will prevent you from sorting your data by time in your database.
4)
In the spring, you will have a gap in the data from 1:59 to 3:00am. This can cause problems if you are
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