Technical data

Installation & Operation Manual GM-TTT

Page 73

7 Optional Modules and Functions

7.1 Colour Lock

Option C: To use this function, the corresponding hardware module must be installed. When

displaying the equipment status (after power-on or when pressing the enter button with the

deactivated menu) it is possible to check, if the module was detected.

Colour framing is performed by using the signal at the VIDEO/BB BNC connector; this signal

is also used for video synchronisation.

Genlock = bb must be activated: In the SET - ... - LOCK menu of the GM-TTT, genlock = bb

is selected and confirmed with enter. Press the genlock button. The colour lock mode is

switched on and off in the same menu.

Colour lock is only provided for the 625/50 TV system. The V4 lock mode is derived from the

burst inserted into the video signal. For the V8 colour lock mode, a luminance signal (white

flag) is expected in line 7, which characterises the first field of the 8 field sequence. Most sync

generators permit to configure the Black-Burst output this way. The luminance pulse should

have a pulse duration of at least 16µs.

The cf LED supplies the following status messages:

LED cf Status

off Colour lock mode is deactivated.

on Colour lock mode is activated, and the corresponding status bit

is set in the time code, i.e. a V8 lock has occurred in the

625/50 TV system.

slowly flashing Colour lock mode is activated, and a V4 lock has occurred in

the 625/50 TV system.

quickly flashing Colour lock mode is activated, but no colour lock has occurred.

As soon as colour lock has occurred, any interference during the detection of the colour

sequence are bridged up to a duration of 10 seconds, then the cf LED starts to flash in short

intervals. Any failure of the video synchronisation will shorten this period to 5 seconds.

When colour lock is activated, every time value set in the generator (manually by using

buttons, by "real-time" coupling or Jam-Sync) is checked and eventually corrected, so that the

address of the colour sequence is maintained. This permits to regenerate continuous external

time values adjusted to a colour framing. If the Jam-Sync function stops, the colour lock mode

is automatically interrupted.