Specifications

August 2010
G4500 BLACKBOX PORTABLE OPERATIONAL MANUAL
102
Integrated FTP Server | Elspec
 Step Time is time in seconds and defines the threshold value. Above
this value, the Time Sync module will simply step towards the new
learned GMT time.
 Manual slew modes contain Master and Slave,-which are manual modes
with the same user control. The only difference is that the defaults are
automatically written in the WEB interface (SLEW Factor and Step
Time fields). While the Master values fit more to a situation of a
BLACKBOX receiving unstable time and acting as an NTP server that
further feeds other BLACKBOX with its learned time, Slave values fit a
situation of a BLACKBOX only acting as an NTP client without further
spreading time to other units.
Time Sync and PQZIP Time Stamping
Since the main purpose of the BLACKBOX Portable is to continuously re-
cord and measure channels for analysis, it is essential to maintain a very ac-
curate UTC time stamp. A PQZIP file is built from time records; typically a
record represents several minutes. Each record contains a beginning and an
end UTC time stamp. Once the Time Sync module detects that time is con-
tinuously drifting beyond a few tenths of milliseconds, the slewing is not
enough to compensate for the drift. Instead, a time step/jump is made and the
corresponding PQZIP record is closed with the old time stamp while a new
record is opened with the new stepped time. Such cases may happen if the
time source (NTP Server/GPS) is unstable or when the communication link
with the NTP server is inconsistent.
Integrated FTP Server
FTP is a file transfer protocol for exchanging and manipulating files over
a TCP computer network. The BLACKBOX Portable uses an integrated FTP
server providing the most convenient computer network standard interface to the
generated PQZip files and auto generated reports. The PQSCADA software sys-
tem makes use of the FTP server interface by automatically downloading PQZip
files.
One of the easiest ways to launch an FTP session, which allows the user to ac-
cess the BLACKBOX Portable’s internal memory, is by using the Elspec Search
utility (refer to Launching WEB or FTP Session on page 141).
Another way is by typing ftp://[device ip address]/ in the Windows Internet Ex-
plorer or Windows Explorer address field.