Specifications
August 2010
G4500 BLACKBOX PORTABLE OPERATIONAL MANUAL
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Time Synchronization | Elspec
The main purpose of synchronizing a BLACKBOX device is to be able to
analyze and compare among multiple devices via the ELSPEC PQSACA-
DA/Investigator system, such as analyzing an event’s source or propagation
over multiple points across the power network.
The following time sources are supported:
Primary NTP Network Server
Alternative NTP Network Server
GPS Receiver
RTC (internal real-time clock)
Typically, the Time Sync module selects the time source automatically per
availability and quality of the existing time sources. However, the Time
Sync module can be configured to work manually and force a specific time
source (explained later in this section).
The NTP Network Server is an external server machine that provides
NTP Clients (such as a BLACKBOX or a PC) a time over IP network
using NTP standard protocol. Time Sync supports two NTP Servers.
The first is acting as primary, and the second is an alternative in case the
primary is not available. NTP server is identified by an Internet (IP) ad-
dress. The BLACKBOX is basically acting as an NTP Client that initi-
ates time requests towards NTP servers. However the BLACKBOX also
acts as an NTP time server, and therefore, it can respond and provide
time for other BLACKBOX units that are configured to its NTP server.
Synchronizing more than 5 BLACKBOX units to the same BLACK-
BOX is not recommended, as it may overload its server. Instead, use a
maximum of 5 BLACKBOX client units to request time from one
BLACKBOX server, and then direct up to 5 others to one of the previ-
ous 5, etc. NTP Time synchronization method is recommended any-
where there is a relatively good internet or intranet communication.
A GPS Receiver is a GPS unit that receives a satellite signal and there-
fore requires special installation with a sky view or transponder from a
GPS receiver with a sky view. A GPS unit provides location and time in-
formation via a serial port (typically RS232/RS485 communication port
to the BLACKBOX). The GPS option is for remote sites where inter-
net/intranet communication is not an option or, alternatively, network
communication is poor.
The RTC is an internal peripheral in the BLACKBOX unit that serves
as a default time source when no other external source available. The