Extron electronics A-4 User Manual download pdf (Page 13)

VSC 150 • Installation and Operation

Installation and Operation, cont’d

termination adapter to the other “input” connector, or

by setting the 75 Ohm DIP switch to On (75 ohms).

The Burst Lock LED lights green to indicate that the

VSC 150 is receiving an acceptable genlock (black

burst) sync signal via the Genlock In connector.

4. Connect oscilloscope (“scope”) probe A to the Genlock

Out connector. This will provide the scope’s reference

signal. In order to avoid altering the genlock signal,

use the cabling configuration that will be used in the

installation. Either connect the genlock signal cable

from the scope to the next device in the system to be

timed, or provide 75 ohm termination at the scope’s

genlock output.

5. Connect scope probe B to the VSC 150’s composite video

output connector. Ensure that the rear panel PAL Out

DIP switch is set for the desired standard (NTSC/PAL).

6. Using the instructions for the scope you are using, set

the scope to view the signals’ horizontal phases.

Adjust the VSC 150’s Horz Phase control until there is

no (0º) difference between the composite video

output’s horizontal sync phase and the genlock signal’s

horizontal phase. See “Oscillocope displays”.

7. Set the scope to view the subcarrier signals. Adjust

the VSC 150’s Sub Phase control until there is a zero

phase difference between the genlock signal and the

NTSC/PAL output. The Burst Lock LED should light.

If the Burst Lock LED does not light at this point,

either adjust the horizontal or subcarrier phases

further, or use a different genlock source.

The color subcarrier adjustment range is ±90° from

0° for a total adjustment range of 180°.

8. View the horizontal phases again. If the phase

difference is not zero, repeat steps 6 and 7 until the

settings do not change.

If the Burst Lock LED does not light at all when

genlock is active and the horizontal and subcarrier

phases have been adjusted to match the genlock

signal, do not continue with this procedure. A

different, more stable or time-base-corrected sync

signal must be used for the genlock timing source.

9. Once the settings are stable and the Burst Lock LED

lights, disconnect the oscilloscope, and reconnect the

genlock cables and terminator to the proper devices in

the system.

2-15

If the genlock connectors are used only for vertical interval

switching, no horizontal or subcarrier phase adjustments

are required, and the Burst Lock LED does not light.

Genlock setup

Genlock differs from simple vertical interval switching in

that an external device (a black burst generator) generates a

reference sync signal for the system, and every device that

uses that signal has its output signal’s horizontal and

subcarrier phases adjusted to exactly match that of the

generator to allow precise timing and full synchronization.

Genlocked systems produce cleaner switches between

inputs than do those without this type of synchronization.

An oscilloscope is required for genlock setup, and a vector-

scope is recommended. Waveform monitors of types other

than a vectorscope may give the appearance that timing is

adjusted correctly when it is 180 degrees out of phase,

which will result in incorrect colors or picture artifacts.

All equipment in the system must be powered up

and turned on for at least 15 to 20 minutes before

genlock setup adjustments can be made and before

the equipment is used in a genlocked application.

To synchronize the VSC 150’s video output with a genlock

signal, follow these steps:

1. Power up and turn on all the devices that will use the

genlock signal. The devices must be on for at least 15

to 20 minutes before proceeding with any adjustments.

To Scope Probe A

and Termination

To Scope Probe B

Computer Video

Signal In

50/60 Hz

100-240 V 0.3A

S-VIDEO

R-Y/B-Y/Y

RGB

R/R-Y

HVS

G/Y B/B-Y

RS-232

OUT

GENLOCK

S-VIDEO

PAL OUT

75 OHM

VIDEO

MAC

VGA

Timing Source

OUT

Cable connections for genlock setup

2. Connect the active timing source signal to the

Genlock In connector on the rear panel.

3. Connect the active computer video input signal to the

appropriate input as explained in step 2 of the Cabling

section on page 2-9. Ensure that the input is properly

terminated either by connecting a local monitor or a

2-14

1 2 ... 8 9 10 11 12 13 14 15 16 17 18 ... 22 23

Comments to this Manuals

No comments

Extron electronics A-4 User Manual Page 13

Comments to this Manuals

Related products and manuals for Network switches Extron electronics A-4