How NEXO integrates ONE, NEO and NEO+ systems in multisite installations

The challenge of a multisite architecture

Several public address and voice alarm systems can coexist in a multisite installation. Each one serves a specific zone, building, unit or operational area, while still forming part of the same environment.

The challenge is to coordinate these systems while preserving the local logic of each installation. A system may need its own announcements, background music, internal messages or local evacuation. At the same time, the operator of the overall site may need a control point from which to act on several areas, launch general announcements or supervise status information.

This type of architecture appears in shopping centres, campuses, hospitals, airports, corporate buildings, hotels, resorts and industrial complexes.

A clear example in shopping centres

A typical use case is a shopping centre. Each shop can have its own ONE system to manage local announcements, background music, internal messages, local evacuation and connection to its fire alarm control panel. Common areas, such as corridors, car parks, entrances or technical areas, may require a NEO+ system with greater integration and operation capacity.

The installation needs each part to operate on its own, while also allowing the whole system to be coordinated from a control point. NEXO connects these system islands within a multisite architecture, adapting the integration mode depending on whether the local system is ONE or NEO+.

What NEXO brings to the whole system

NEXO acts as the link between local systems and control points. To do this, it uses ACSINet, LDA’s technology for transporting audio and control data over an Ethernet network.

ACSINet can be understood as the layer that coordinates distributed systems. NEXO connects each island to this higher-level architecture and adapts the integration according to the type of local system.

How ONE and NEO are integrated through NEXO Hub Lite

ONE is a compact solution for installations that need public address and voice alarm with local operation. Thanks to NEXO, it can now be integrated into a multisite architecture and used in independent spaces where a dedicated local installation is required, while still being connected to the wider system.

According to the NEXO manual, ONE and NEO systems based on ACSIv1 can be integrated through NEXO Hub Lite. This feature is included as standard, with no additional licence, and allows NEXO to be used as the cluster receiver in Gateway to ACSIv1 Site mode.

In practice, NEXO acts as a gateway between the central level of the architecture and the local ONE system. ONE identifies NEXO as two virtual ACSIv1 devices:

• an MPS-8Z microphone for general public address calls;
• a VAP-1 voice alarm panel for emergency calls and actions.

This allows ONE to retain its local operation and receive requests from the higher level of control when the project requires it.

Scope of the ONE integration

Integrating ONE through NEXO Hub Lite allows ACSIv1-based systems to be connected to a multisite architecture while maintaining a clear relationship between the local system and the central control point.

Voice requests from microphones connected to the cluster can be transmitted from the central control point. Available ACSIv1 microphone functions can also be sent, including VAP-1 fire panel functions for emergency calls.

From the ONE system to the central level, the general EMG and FLT statuses are distributed. The link between NEXO and the ONE system is also supervised through the ACSIv1 bus.

There are limits to this integration mode: specific information about zones or groups is not transmitted, VAP1-FES cannot be used, button assignment to zones or groups cannot be customised, and triggers or events cannot be launched.

Why we recommend the full NEXO Hub licence for NEO+

NEO+ is designed for medium and large projects with greater integration, scalability and operational requirements. In a multisite architecture, it can cover common areas, main buildings or areas where greater control capacity is required.

When the remote system is NEO+, the recommended option is to use the full NEXO Hub licence in Gateway to Domain ACSINet mode. In this case, NEO+ works natively within ACSINet, making better use of the system’s capabilities.

This approach provides greater simultaneous operation:

• up to 16 simultaneous microphone calls, one to each connected Domain;
• up to 56 simultaneous BGM audio channels.

It also distributes EMG, FLT and DIS statuses, while ACSIv1-based integration works with EMG and FLT. Link supervision and fault notification to the NEO+ system are also included.

When to use NEXO and when to use a NEXO Hub licence

The choice depends on the system to be integrated and the role it will play within the project.

Both approaches can coexist in a mixed architecture. ONE can serve local spaces where compactness and autonomy are priorities. NEO+ can cover areas of greater scale or complexity. NEXO brings these pieces together within a coherent multisite architecture.

An architecture designed for distributed projects

Many installations grow by buildings, zones, units, phases or extensions. This makes it useful to have an architecture capable of integrating compact systems such as ONE and scalable systems such as NEO+ under a common operational criterion.

NEXO helps build that bridge between local autonomy and centralised management. For LDA, this approach forms part of a broader vision of audio for safety: designing public address and voice alarm systems that respond to the real use of the building, its operational needs and the future evolution of the project.

Are you designing a multisite audio for safety architecture?

Contact the LDA team to review which integration mode best fits your ONE, NEO+ and operational requirements.

FAQ: multisite system integration with LDA NEXO