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Appendix D: Understanding External Audio Interface
External Audio Interface (EAI) provides a connection for analog audio from a field device directly into a console
position. With the Avtec USB NENA Jack Box, the external audio interface functionality is physically built into the
device; the EAI and jack box function as separate components.
When viewing the device from behind, the traditional jack box functionality is located on the left side of the device.
Likewise, the external audio interface functionality is located to the right. The external audio interface provides
connectivity for NENA devices.
NOTE
When connecting multiple USB NENA jack boxes at a Scout console position, only one jack box can be configured
to enable external audio interface.
Contrasting Traditional Audio with EAI Audio
The USB NENA Jack Box provides traditional jack box functionality (audio exchange between a dispatcher and VPGate
endpoint). Additionally, the device provides a direct audio exchange between a dispatcher or VPGate endpoint in a
patch and a device via external audio interface, such as a NENA device.
The following diagram illustrates how audio flows in a traditional jack box system that incorporates VPGate as opposed
to a USB NENA Jack Box utilizing the external audio interface functionality.
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Avtec USB NENA Jack Box Configuration Guide
| October 2021 | Revision 9