NEXUS – XCPU – The concept:

Exactly one XCPU board is used for each basic device. This takes over control and monitoring of all modules in the base unit as well as the system administration of the unit itself. It also generates the NEXUS system clock and, if necessary, controls synchronization to the currently selected external clock source. All states of the entire NEXUS system are available at any time and on each individual XCPU module in the network; all volatile data are always stored immediately in a battery-buffered SRAM. This concept guarantees that a total failure can never occur in a NEXUS system and that, for example, newly switched-on base devices are ready for use and informed about everything within a few seconds.

Any XCPU card in the network can be used to connect external control computers or systems, from the native Matrix-5 control interface to the most complex control systems used in broadcasting stations. Integration into an SNMP system is also possible, which significantly enhances the already comprehensive security and monitoring functions of NEXUS networks. The board has an internal level and noise generator so that routing tests can also be carried out without external signals.

For the level measurement, the XCPU module determines and calculates the level data of the inputs and outputs in its base unit. Due to the increased computing power from hardware version 09, the XCPU card can also perform tasks such as loudness metering and spectral analysis.

NEXUS – XCPU – Features:

Signal generator for system-wide use This central module provides a system- wide test signal, which consists of a sine tone with adjustable level and frequency, a white or pink noise.

NEXUS Logic Control as integrated media control.

NEXUS Logic Control can be used to program the simplest to very complex interactions and automatisms. Each base device has an autonomous logic unit that communicates with the entire NEXUS system. For example, the status of crosspoints can be evaluated or the level of specific signals can be monitored. In conjunction with other NEXUS boards, certain additional functions are available. For example, the XRI can be used to query and set relay inputs. The XCI offers the possibility to evaluate or send serial signals.

In combination with complex conditions, Logic Control can trigger almost any control function in the entire NEXUS network, such as switching relay contacts, setting crosspoints, setting levels, or even controlling mixer functions. Among other things, this can also be used to integrate NEXUS into comprehensive external emergency systems or to trigger alarms.

Extensive internal and external synchronization options The NEXUS system can be synchronized and the internal clock can be output via the integrated word clock inputs and out- puts. The board can also synchronize the NEXUS system to any digital input. A sync hierarchy can be created so that, in the event of a source failure, an uninterrupted and inaudible fade over to the next sync source.

System state fail-safe memory All volatile data is immediately stored on a battery-buffered SRAM memory and is retained in the event of a power failure or switch-off. This means that the system boots immediately to the last operating state and is ready for use again within seconds.

Ethernet and USB ports for connecting external control systems.

The operating computer can be connected via the Ethernet and USB ports. All NEXUS functions can be controlled with the corresponding matrix operating program. In addition, external control systems can be connected via these interfaces.

Determination of level data for level indication The level measurement data converge on the XCPU card and can be visualized via the operating program.

NEXUS – XCPU – Use cases:

System-wide level monitoring of any NEXUS I/Os.

The XCPU calculates the level data of the inputs of the respective base device. By exchanging data with the other XCPU boards in NEXUS, each XCPU can monitor and display the channel levels of the input and output boards of the entire audio network. The XCPU forms the intelligent control center in each NEXUS base device: the operating computer is connected here to display level values and allow the user to change all parameters and query statuses. The XCPU boards communicate with each other via the fiber-optic network and exchange information on the status of the boards, control information, and the central synchronization clock.

Managing the most complex networks without a single point of failure

An overall failure of a NEXUS network cannot be caused, especially by the failure of a single base device, because each XCPU knows the state of the entire system at any given time. Due to the burning in process, which is part of the commissioning process, the control board has the information about the number of NEXUS Base Devices, the boards they contain, and the intended network topology, so discrepancies can be detected immediately. This means that if, for example, the power supply of a base device fails, only the base device and the associated I/Os are affected. Maintenance and operation can be performed from any point in NEXUS because the XCPU continuously exchanges status information from the base devices.