Extron Electronics VTG 400D_400 DVI User Guide - Manual (Page 33)

2-23 VTG 400D/400 DVI • Installation and Operation
The following test patterns have a special feature function using the invert
button:
• SMPTE Bars — This pattern toggles blue mode on and off.
• Bounce (manual toggle) — Toggles the center window on and off. This
pattern does not invert the entire pattern.
• Contrast transfer function — This test pattern toggles the vertical lines
between always on and blinking.
Refer to the Test Patterns in Detail section in appendix A of this manual.
Adjusting the video level of test patterns
From the default cycle menu, the video level of specific test patterns can be
adjusted in 1% increments (1 IRE) from 0 through 100% (0 to 100 IRE). Currently,
there are six test patterns that support this adjustable level feature.
• Window (variable level)*
• Flat field*
• Flat field with targets*
• Checkerboard*
• Contrast transfer function
• Hum bar detect
* These test patterns have globally adjustable video levels, i.e., a change to one
results in an identical change to all of the others.
Adjusting the level of the contrast transfer function test pattern results in
changes to the contrast ratio percentage rather than the video level. The
hum bar detect and contrast transfer function levels are saved
independently, so changes to other patterns’ video levels do not affect these
two patterns.
Use the adjacent arrow selection buttons to adjust the video level, as shown here
in the example display.
RES: VESA 8 1024x768
FRQ: 60.00kHz 75.00Hz
Checkerboard 0%
SIG: Freq. Sweep SPD:9.0 sec
LEV: -09 dBu 275mV
Refer to the Test Pattern Chart in appendix A for the table of available test
patterns and their features.
Scope-Trigger buttons
A unique feature of the VTG 400 is the ability to locate a trigger point at a specific
pixel location on an oscilloscope’s signal display.
When a Scope Trigger button is pressed, the LCD displays the Scope-Trigger
menu, as shown in the following figure. The cursor’s location is given in
coordinates (x, y) relative to the active area, as well as the total area of the
screen display. The range of the coordinates is dependent on the scan rates.
Connect the VTG 400’s trigger output to the external trigger input on the
oscilloscope. The trigger on the scope should be set for rising edge ( ) slope.