> ## Documentation Index
> Fetch the complete documentation index at: https://docs.solidyne.ar/llms.txt
> Use this file to discover all available pages before exploring further.

> Remote signal handling. Peripheral control.

# GPIO Signals

## USB Control

The **USB I/O (GPIO USB) interface** is an accessory sold separately (consult your dealer).

* Features 2 inputs and 2 outputs for control.
* Allows external control of AUDICOM transport functions.
* AUDICOM can also send commands to control external devices.

Example: for consoles that transmit control signals, these can be used to control playback in AUDICOM.

* When opening the fader or enabling the on-air button, AUDICOM starts playback.
* When closing it, playback stops.

<Note>
  Command sending and receiving must be enabled from AUDICOM's configuration panel.
</Note>

<img src="https://mintcdn.com/solidyne/WeNkIa-qZtPC3jmc/images/audicom/au-USB-GPIO.jpg?fit=max&auto=format&n=WeNkIa-qZtPC3jmc&q=85&s=6cc46185aaba545790f5d31ab7a3a485" alt="AUDICOM USB GPIO" title="AUDICOM USB GPIO" className="mx-auto" style={{ width:"44%" }} width="444" height="489" data-path="images/audicom/au-USB-GPIO.jpg" />

### Warning

<Danger>
  The ground terminals of the USB interface share the ground with the PC's USB port.\
  Not being internally isolated, they may expose the computer's USB ground potential.

  * Verify circuits before making connections.
  * Reverse voltage or high spikes can damage the interface or computer.
  * Outputs provide 5V with 250 Ohm internal resistance to limit current.
  * Inputs are **dry contact**, switched by direct connection to ground.
</Danger>

***

## Remote Signal Handling Options

### Internet Link

A "head" station can control a "relay" station that only replaces commercial breaks with local content.\
More details in the **Internet Tools** chapter.

### Remote Blocks

Previously called "satellite". Automates switching between local audio and an external source (satellite, streaming decoder, etc.).\
Also allows controlling relay stations.

Available modes:

* **SatFill**: time-based switching.
* **SatSlave (Master-Slave)**: centralized control of remote terminals.

The **Multicast** module handles direct transmissions to stations via Internet (see Internet Tools).

### SatFill Remote Block

* Used when switching between local programming and external sources (satellite, point-to-point links, etc.) is needed.
* These blocks appear as **SYNC** in the On-Air Screen.
* While the SYNC event is active, the external signal plays.
* When finished, AUDICOM resumes local CyberPlay programming.

### SatSlave Remote Block (Master-Slave)

* Allows linking AUDICOM terminals in different locations.
* Master terminal sends command using **/REGIONAL** instruction, generating a pulse via USB I/O (e.g. GPO).
* Slave terminals switch between Master programming and local programming.
* Last block can be programmed as **Syncro**, ensuring time-based switching if pulse is not received.

### External Signal Retransmission with SatFill

Example: an on-air terminal switching between local and satellite signal.

Switching methods:

**a) Controlling console modules via USB port**

* External signal enters a console module.
* AUDICOM sends commands through USB interface to activate/deactivate VCA modules.
* Connections:
  * **Data**: USB interface ↔ console.
  * **Audio**: satellite signal and local signal to console modules.

**b) Software switching of line input**

* External signal enters a soundcard line input.
* AUDICOM switches between that input and local audio.
* Controls only one input; multicard required for more signals.
* On console: PGM-1 output for local audio, line input for satellite.

### Streaming Retransmission with SatFill

AUDICOM supports **iLink** blocks for direct audio streaming playback.

### Remote Station Control from Master Terminal

Configuration based on SatSlave blocks:

* **Master Terminal**: sends program signal and control pulses.
* **Slave Terminal**: receives programming and switching commands.

Master finds /REGIONAL and changes a port output (USB or parallel), transmitting the order to Slave.\
Slave switches between satellite signal and local programming.

#### Central Terminal (satellite uplink)

<img src="https://mintcdn.com/solidyne/WeNkIa-qZtPC3jmc/images/audicom/au-subida-sat.jpg?fit=max&auto=format&n=WeNkIa-qZtPC3jmc&q=85&s=fa7fb0cb4cc9b6b115ade629ff061f02" alt="Au Subida Sat Jp" title="Au Subida Sat Jp" className="mx-auto" style={{ width:"57%" }} width="617" height="354" data-path="images/audicom/au-subida-sat.jpg" />

* USB interface connections described in **USB Control Signals**.
* /REGIONAL input changes state (e.g. SAT-1 DataBit 2) and can switch audio console.
* Can also input directly to audio card without console.

#### Remote Terminals (satellite downlink)

<img src="https://mintcdn.com/solidyne/WeNkIa-qZtPC3jmc/images/audicom/au-sat-bajada.jpg?fit=max&auto=format&n=WeNkIa-qZtPC3jmc&q=85&s=9a0005bd1ad9e7b80b2d4d5d9f09dc01" alt="AUDICOM satellite-downlink" title="AUDICOM satellite-downlink" className="mx-auto" style={{ width:"60%" }} width="644" height="340" data-path="images/audicom/au-sat-bajada.jpg" />

* USB interface connections described in **Parallel Port Control**.

#### Control Command Configuration

* With multiple sound cards, you can define which line input will be used for satellite blocks.
* Configure in `Audicom.ini` under `[Hardware]` section:

```ini theme={null}
[Hardware]
LineInID=0
```

* Value `0` indicates Windows default card.
* Value `1` corresponds to second card, though order may vary by Windows enumeration.
* In some cases, trial and error may be needed to determine desired input.