Grass Valley TTN-HDS-1616 - Manual (Page 19)

HDS-1616 Rev. 0
11
SDV layer 3 Input SDV layer 3 Output
1 9 1 9
2 10
2 10
3 11 3 11
4 12 4 12
SDV layer 4 Input
SDV layer 4 Output
1 13
1 13
2 14 2 14
3 15 3 15
4 16 4 16
5.3 Vertical interval trigger
The HDS-1616 router allows VIT switching for both SDTV and HDTV.
The HDS-1616 accepts only standard analogue black-burst/composite sync/composite video signals in
525/30, 525/29.97 or 625/25 format as the VIT reference.
In order for VIT switching of HDTV signal to work, the HDTV signal must have both the same frame-
rate and Vertical sync timing (Ov incident) as the applied VIT reference.
Since the line duration is different for the HDTV signals and the VIT reference, the actual switching time
is timed from the Ov incident.
Switch 1 and 7 on the configuration switch set the VIT mode. The modes can be switched according to
the following pattern:
- means switch down (OFF)
* means switch up (ON)
DIP-SW pos. 1 DIP-SW pos. 7 VIT 525/625 line Switch timing
Don't care
ON (SDTV) 525 30uS ± 5uS after Oh line 10
Don't care ON (SDTV) 625 30uS ± 5uS after Oh line 6
OFF (line 4) OFF (HDTV) 525 10-15uS after Ov. *
OFF (line 1) OFF (HDTV) 625 12-17uS after Ov. **
ON (line 6/7) OFF (HDTV) 525 187-192uS after Ov. ***
ON (line 4) OFF (HDTV) 625 225-230uS after Ov. ****
* May be used for line 4 switching for the 30Hz and 29.97Hz frame-rates of SMPTE 260M and SMPTE
274M.
** May be used for line 1 switching for the 25Hz frame-rate of SMPTE 274M and SMPTE 295M.
*** May be used for line 6/7 switching for the 30Hz and 29.97Hz frame-rates of SMPTE 260M and
SMPTE 274M.
**** May be used for line 4 switching for the 25Hz frame-rate of SMPTE 274M.