GUIDE TO INSTALLATION AND OPERATION
DAP-781i |
11
2.5.2 Remote
analog
controlled tracking delay
For compatibility with previous video processors, like the DVP-101i and ASD-231i, the DAP-781i has an analog
tracking delay input on the rear RJ45 jack. An ABUS connection at the front of the DAP-781i overrides this input.
The module can delay the signal up to 2.73 sec (@48 kHz). A part (320 ms for 8 video frames) of the maximum
delay is reserved for the tracking delay.
The applied delay is the sum of a fixed user-adjusted delay (in 1 ms steps or on a sample-by-sample basis) and
a tracking delay coming from the video processor.
This signal is sent via an RS 422 path.
Video Processing Module
Audio Processing Module
VPD signal
VPD signal
Figure 14 :
Tracking signal
The signal period corresponds to the maximum delay reserved by the main module (T) and the positive pulse
width (tproc) corresponds to the required delay. For a sudden variation, DAP-781i integrates this modification
within 15 sec for a variation of 40 ms.
t
PROC
(MIN)
T (period)
t
PROC
(MAX)
t
LOW
t
PROC
Figure 15 :
Timing chart
The reserved part (T) of delay is subtracted from the accessible maximum fixed delay value. Up to four cards
can share the same tracking signal.
2.5.3 GPI
Outputs
Four open-collector GPI outputs (one for each channel) are available on the GPI socket. For each channel, the
output is dedicated to a no-lock condition on the digital input. In the absence of alarms, no current flows through
an output pin. These outputs are inactive when the alarms are disabled (ALRM menu, OFF selected).
