Dolby Laboratories DP571, DP572 Main Out, PCM Delay Out, Status, Pin Connection Explanation

Dolby E Multichannel Distribution System User Manual DP571 Dolby E Encoder

3.1.7Main Out

The encoded Dolby E bitstream is output from the rear-panel Main Out connector as an AES3 coaxial digital signal. Two connectors are available for transmission of Dolby E data to multiple decoders or monitoring units.

Note: The two Main outputs are electrically separate, not passive loop-through connections, so there is no need to terminate an unused output.

3.1.8PCM Delay Out

Encoding delay is added to the PCM signal transmitted from the PCM Delay Out connector. The DSP subsystem calculates the delay equivalent to the main channel latency and applies it to the PCM Delay Out.

3.1.9Status

General Purpose Input/Output (GPI/O) signals for the DP571 are available from the Status port, a female DB-9 connector. The input and output signals are 0 – 5 V TTL. The pin configuration is defined in the table below:

Table 3-1DP571 Status port pin functions

Pin	Connection	Explanation
1	Preset Tally A	Preset tally output
2	Reference Video Valid	1: Valid;	0: Ref video error
3	Dolby E Encoding Valid	1: Valid;	0: Encoding error
4	System Operational	1: Functional;	0: Failed
5	Fault	1: Functional;	0: Hardware fault
6	Preset Tally B	Preset tally output
7	Preset Ctrl A	Preset control input
8	Preset Ctrl B	Preset control input
9	Ground

Using the Status Port to Select Presets

The two inputs on pins 7 and 8 select among the first three (of eight) presets stored in the DP571. The inputs are normally high (internal pull-up) and trigger a preset recall by sensing a momentary high-to-low transition. A momentary contact closure between pins 7 and 9 (ground) or pins 8 and 9 is sufficient to activate a function but a held closure also works. A low-to-high transition (i.e., a switch release) is ignored. Table 3-2summarizes the operation of the two inputs.

3-4