Datasat XD20, Инструкция по установке и эксплуатации

Страница: 239 / 254

TITLE
Timecode Reading Problems
NUMBER
TN-E698
REV
B
DEPARTMENT
Engineering
CREATED BY:
K. Hultgren
EFFECTIVE DATE
January 23, 2009
APPROVED BY:
L. Brown
Appendix L. Technical Notes L-9 Document #: 9301H264001.1
Checking timecode with an oscilloscope
Connect option 1 Remove the timecode reader cable’s connector shell from the reader end.
Connect the scope probe to Pin 1 and the scope ground to Pin 6.
Connect option 2 If using the “DTS timecode reader-to-oscilloscope adapter” (DDE P/N D729),
simply disconnect the timecode cable from the reader head. Connect the adapter
to the reader head (male DB9) and connect the timecode cable to the other end of
the adapter (female DB9). Then, connect the BNC to the oscilloscope.
1. Set the scope to 0.5V/division, sweep at 0.5mS/division, and the trigger to internal.
2. Run a reel of time-coded film (BILL and BUZZ reel is recommended) and observe the timecode
cells. The amplitude should be constant and at
4 Volts Peak-to-Peak . The cells should be
visible all the way to the right of the scope screen. The cross-points (“X”s) should be well
defined (FIG. 1). Poorly defined cells are shown in FIG. 2. They are caused by film bounce and
jitter through the projector or from the platter
/
reel.
FIG. 1 GOOD TIMECODE FIG. 2 POOR TIMECODE
500mV/DIV 0 . 5mS/DIV 500mV/DIV 0.5mS/DIV