Dolby Laboratories DP524 Manual de usuario descargar pdf (Pagina 34)

DP571 Dolby

E Encoder User’s Manual Hardware Description

6.2.1 Status Connector

The DP571 status port provides general purpose input/output (GPI/O) signals through

a 9-pin female D-connector. The input and output signals are 0–5 V TTL. The pin

configuration is defined in Table 6-3.

Table 6-3 DP571 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 control A Preset control input

8 Preset control B Preset control input

9 Ground

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 (that is, a switch release) is ignored.

Table 6-4 summarizes the operation of the two inputs.

Table 6-4 Status Port Preset Selection

Pin 7 Transition Pin 8 Transition Preset

High to low None or low to high 1

None or low to high High to low 2

High to low High to low 3

Choosing presets 1–3 also generates corresponding output on the status port that can

be used to specify a preset through the status port or front panel. A high level for both

outputs indicates a preset selection other than 1–3 (or no preset). Table 6-5

summarizes the two outputs.

6-4

1 2 ... 29 30 31 32 33 34 35 36 37 38 39 ... 44 45

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Dolby Laboratories DP524 Manual de usuario Pagina 34