PacketFive | Cnuas Virtual AI/HPC Infrastructure Cnuas Facility Twin, Datasheet Campus digital twin, OpenUSD scene generation, power model and live ORV3 telemetry Document DS-CNU-030 Revision A Issued 03 August 2026 Status Published ============================================================================== Item Value --------- --------------------------------------- Part cnuas-facility Type Facility digital twin and power model Package cnuas-facility, version 0.1.0 Version 9fbdddf-dirty Repo PacketFive/cnuas 1. Overview The facility twin generates a hyperscale AI and HPC data centre campus as an OpenUSD scene, computes its electrical and thermal load, and animates the scene from live readings taken off the emulated Open Rack V3 power shelf. It is what connects a rack of emulated hardware to the site scale question every operator eventually asks: how much power does this draw, and what has to be built to supply it. The scene opens in any OpenUSD capable viewer, including NVIDIA Omniverse and Isaac Sim. Key features - Declarative campus specification, from site dimensions down to rack rows. - Three building footprints, the I, H and E shapes hyperscale operators build. - Data halls with rack rows, cold and hot aisle spacing, and support rooms. - Site features: yards, roads, plant compounds, groves and lakes. - Power roll-up from rack to hall to building to campus, with plant sizing. - Live sampling of the emulated Open Rack V3 shelf over Modbus, written back onto the scene as typed attributes. 2. Module map Module Responsibility ------------ ------------------------------------------------------------------------------- spec.py Declarative campus, building and hall specification, and the reference campus catalog.py Equipment catalogue, dimensions and power rating per rack and plant type plan.py Resolves a specification into placed rooms, racks, plant and roads layout.py Rectangle mathematics, building footprints, rack row layout geom.py Geometry and material primitives usd.py Writes the campus OpenUSD scene graph schema.py The cnuas: attribute namespace carried on the scene power.py Load roll-up and plant sizing orv3.py Modbus client and register decoding for the power shelf live.py Samples the shelf and animates the scene units.py Named dimensional constants cli.py Command line front end 3. Command reference Command Purpose --------- ----------------------------------------------------- build Write the campus OpenUSD stage power Print the power roll-up rooms Print the room programme live Sample the Open Rack V3 shelf and animate the stage 4. Scene specification Parameter Reference value ---------------------------------- ------------------------------------------------------------------------------ Campus name Cnuas Ridge AI Campus Site footprint 1000 m by 800 m Buildings 3, one each of the I, H and E footprints Data halls 16 across the three buildings Design power usage effectiveness 1.15 Target campus load Close to 300 MW Stage root /World Scene branches /World/Looks, /World/Site, /World/Yards, /World/Buildings, /World/Prototypes Default output format .usda, with .usdc and .usd also supported 5. Equipment catalogue Entry Rated load --------------------------------------------------------------------------------------------------------------------------------- -------------------------- Cnuas Open Rack V3, 24 OpenU 6 kW GB200 NVL72 class rack 132 kW Storage rack 12 kW Network rack 15 kW Medium voltage switchgear, transformer, generator, coolant distribution unit, fan wall, indirect evaporative cooler, dry cooler Sized by the power model 6. Power model Quantity Definition ----------------------------- ------------------------------------------------------------------------- Information technology load Sum of rack ratings in scope Facility load Information technology load multiplied by the power usage effectiveness Overhead Facility load less information technology load Heat rejected Equal to the information technology load Density Load per unit floor area Roll-up functions run at hall, building and campus scope. Plant counts are derived from the resulting load. Plant Unit size used for sizing --------------------------- --------------------------- Generator 3000 kW Cooler 3500 kW Coolant distribution unit 2000 kW 7. Live telemetry Item Value --------------------------------- -------------------------------------------------------------------------------- Source Emulated Open Rack V3 power shelf Protocol Modbus remote terminal unit framing Transport Serial line or a TCP endpoint, by default port 3485 on the loopback address Decoded from the power supply Voltage, current, power, fan speed, temperature Decoded from the battery backup State of charge and unit state Write back Typed attributes in the cnuas: namespace on the corresponding scene primitives The shelf itself is emulated by the BMC stack, which runs the power shelf firmware and presents the RS-485 segment. 8. Validation Area Test Cases -------------------------------------- ---------------------- ------- Power roll-up and plant sizing tests/test_power.py 8 Footprints, rectangles and rack rows tests/test_layout.py 17 Scene graph generation tests/test_usd.py 13 Shelf sampling and scene animation tests/test_live.py 21 All 59 cases pass. See the Validation Matrix. 9. Operating notes - The twin models geometry, load and telemetry. It does not perform computational fluid dynamics, electrical fault studies or structural analysis, and the plant counts are sizing estimates rather than engineering designs. - Building footprints are limited to the I, H and E shapes in this revision. 10. Integration information Item Value -------------- -------------------------------------------------------------- Repo PacketFive/cnuas Source facility/src/cnuas_facility/ Entry point cnuas-facility Python 3.10 or later Dependencies OpenUSD Python bindings Viewers Any OpenUSD viewer, including NVIDIA Omniverse and Isaac Sim 11. Revision history Revision Notes ---------- --------------------------------------------------------------------------------------------------- A First publication. Reference campus, catalogue ratings and plant unit sizes read from the source. ============================================================================== PacketFive, Packet Five Networks Ltd., Dublin, Ireland. Cnuas Virtual AI/HPC Infrastructure is published at https://github.com/PacketFive/cnuas under the Apache License 2.0; read it at https://github.com/PacketFive/cnuas/blob/main/LICENSE. Cnuas Virtual AI/HPC Infrastructure is emulation software. It is not affiliated with, endorsed by, or derived from any hardware vendor, and every device it models is a software artefact. The work is published by its authors in a personal capacity and is not sponsored or endorsed by any employer. Specifications describe the referenced revision of the software and may change without notice. Contact info@packetfive.com.