Cnuas Facility Twin, Datasheet
| Item |
Value |
| Part |
cnuas-facility |
| Type |
Facility digital twin and power model |
| Package |
cnuas-facility, version 0.1.0 |
| Version |
fd0f896-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.
| 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. |