Tektronix TG700, Руководство пользователя

Страница: 220 / 343

GPS7 GPS Synchronization and Timecode Module
adding or subtracting a speci fi ed amount from the current value. The scheduled
date and time of the change must be programmed into the GPS7. For example,
to change to daylight savings time, schedule the system to add one hour to the
time zone offset at 02:00:00 (local time) on March 8, 2009. To return to standard
time, schedule the system to subtract one hour from the time of day offset at
02:00:00 on November 1, 2009. At the scheduled time and date, the DST change
is added to the time zone offset as seen from the instrument display. You can then
program the next scheduled DST change.
VITC may have DST shift already applied. To avoid duplicating DST shifts,
disable the DST SCHEDULER if the time of day reference has DST applied.
Task Scheduler. The task scheduler is responsible for triggering scheduled
events at the appropriate time. This includes DST changes, deferred leap second
adjustments, and triggered alarm outputs.
SNTP Server.
The GPS7 includes an implementation of the Simple Network Time
Protocol (version 3.0), using the network interface of the TG700 mainframe. The
SNTP server is automatic; when the Master time is set to GPS and the GPS7
acquires a valid time, the server will respond with valid SNTP packets to time
requests from NTP clients. When the Master time is set to GPS, the server always
responds with UTC time only. It is the responsibility of the NTP client (PC
workstation,
fi le server, etc.) to be con fi gured with the correct time zone offset.
The SNTP Server will also respond with valid SNTP packets when the Master
time is set to Internal mode.
When using VITC input as the time reference, the SNTP service is not available.
TC Offset *. Every timecode output has an independent offset (hours, minutes,
seconds, frames) that can be added to the value of the selected timecode source.
TC Engine.
The timecode engine runs at the rate speci fi ed through the user
interface and generates the actual timecode bits needed for each output.
LTC.
The GPS7 module has four independent linear timecode outputs. Each
output can be set independently with regard to timecode format, module timing,
and timecode delay.
Analog Black. The GPS7 module has three analog sync outputs. Each output
can be con fi gured as NTSC or PAL black burst (with optional VITC insertion)
or HD trilevel sync. The BG7 module has four analog sync outputs which can
be similarly con
fi gured.
HD-SDI.
The standard HDVG7 module has one HD-SDI test signal generator
(with two outputs), for which ancillary timecode (ATC) can be added. If Option
BK is available, then there are two independent HD-SDI test signal generators
available.
3–108 TG700 TV Signal Generator Platform User Manual