Tektronix VITS100 Passing Program Video Auto VIRS Inserting a Source ID

Operating Basics
2–4 VITS100 NTSC VITS Inserter Instruction Manual
In addition to internally generated test signals, the VITS inserter can pass video
signals that are already in the vertical interval of the program video. This
includes the delete/insert lines, which are lines 17 through 20 in all fields.
When AUTO VIRS is selected, the instrument automatically checks the assigned
line and field of the incoming video for a VIRS signal. If VIRS is detected, the
line is passed with no processing. If VIRS is not detected, the internally
generated VIRS signal is inserted onto the line.
Source identification can be inserted on any of the available vertical interval
lines. The “Source ID” consists of sixteen equal-duration flags that can be set
high or low with the rear-panel SOURCE ID switches. Source ID is set by the
user to provide a visual identification of the signal path. Some equipment, such
as the Tektronix VM700A Video Measurement Set, can use this signal to
generate an alpha-numeric ID on the screen display or on printed reports. Figure
2–3 shows the waveform of a source identification code that is generated when
all switch segments are set ON.
Volts
0.5
0.0
10.0 20.0 30.0 40.0 50.0 60.0
MicroSeconds
Source Identification
Switches all on
(S/N 8020244 and below)
(S/N 8020245 and up)
0.0
Figure 2–3: VITS100 NTSC VITS Inserter source ID signal
Passing Program Video
Auto VIRS
Inserting a Source ID