Optically-isolated Digital Inputs

The digital input connections are implemented as four + and – terminals on 3.5 mm captive screw terminal blocks. Because each input is optically-isolated, both connections must be used to ensure the correct operation of the input circuit.

NOTE: By factory default, status notification for Digital Inputs 1 through 4 is disabled.

To be made operational, they must be enabled using the Set input trigger

on MSVPP command (see “Applicable MSVPP Commands”).

The optically-isolated input circuits provide for various connection scenarios; two common methods follow:

Option 1 — Figure 76 shows a typical Digital Input application, monitoring external switch positions. This application uses the Power port on the media player and is an application where the current required is within the 1.8 A that the Power port makes available for external use.

Switch 1

Switch 2

Screw Terminals

JMP 9600 Digital Inputs

1

2

JMP 9600 Power

JMP 9600 Input Terminals

1 kohm

+12V

GND

Internal Configuration

Figure 76. Digital Input Connection Using the Power Port

Option 2 — Figure 77 shows a similar external switch monitoring application, except that it uses an external power supply. The external power supply is the preferred method in noisy environments or when wiring is run over a long distance. The exact external power supply voltage rating is not critical so long as the current through the 1-kohm resistor internal to the media player is limited between 5 mA and 20 mA. Note the resistor in the input 1 circuit in figure 77, which attenuates the current to within these limits.

+24 VDC PS +VE

-VE

+5 VDC PS

+VE

-VE

680 Ohm

Switch 1

 

Use twisted pair

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+5VDC

wire for noise

Screw Terminal

 

 

cancellation.

 

 

 

Switch 2

 

 

 

 

NOT

USED

JMP 9600 Digital Inputs

1

2

JMP 9600 Power

+12V

GND

JMP 9600 Input Terminals

1 kohm

Internal Configuration

Figure 77. Digital Input Connection Using External Power Supplies

JMP 9600 Media Player • Detailed System Interaction

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Extron electronic JMP 9600 manual Optically-isolated Digital Inputs, Digital Input Connection Using the Power Port