Data centre audits fail for one reason: the register says U24, the rack says U5, and nobody noticed for six months. VigiStock closes that gap. A U-Rack Strip inside each rack senses U-SENSE tagged devices at every U-position and streams what it sees to the VigiStock server over an encrypted link. The web console shows each room, rack and U-slot live, flags doors left open, catches unauthorised swaps and removals, and lights the rack's own LEDs so technicians put hardware where the plan says. Handheld RFID and QR scanning still cover everything the strips do not.
See your own rack on the screen
30-minute demo, or a site assessment for a pilot rack. WhatsApp, or email us.
One platform, six layers. This page is layers 5 and 6.
VigiStock is one install: one asset register, one location tree, one audit trail, one Android app, one evidence pack. Each technology below writes into that same record. Start where you are, add a layer when the use case demands it, never re-platform.
Layer 1Register & evidenceLocation tree, fixed-asset register, custody, trace report, evidence PDF Layer 2QR identityPhone camera; every asset, drive, spare; photo and GPS evidence Layer 4UHF gate readersDock, hall and cage events; gate rules and violation webhooks Layer 5
U-SENSE in-rack sensingPer-U continuous presence, door, swap, departure, strip-sourced trace
Layer 6Guided operationsReservations, LED guidance, U-slot verify, server lifts, extended sensing
Rack and room visualisation
VigiStock models the data centre as a location tree: Building, Floor, Room, Rack, U-slot. A rack is both a location (it holds devices) and a capital asset (it appears in the Fixed Asset Register with depreciation). Each U-position is its own slot, so a device's move from U24 to U5 lands in the same audit trail as any other asset movement.
Room Layout: rack tiles with occupancy ring and per-U faceplate strip. Rack 13's door is open: red flag on the tile, red banner across the console, audible alert until acknowledged.
| View | What it shows | Live updates |
|---|
| Rack Elevation | One rack, bottom to top, every U-slot. Multi-U devices render as one block of the right height. Occupied rows link to the asset record. Door badge, per-strip link health, Verify Now button, Reserve and Release actions, pending-swap approvals. | Live, pushed as events happen |
| Room Layout | Drag-and-drop floor plan of one room. Each rack tile shows an occupancy ring, a device-faceplate strip per U, and a red door-open flag. Layout can be locked per room so nobody drags a finished plan out of place. | Live, refreshed every few seconds |
| Row View | Whole room, racks side by side in floor-plan order, read-only. Sidebar per rack: door, controller, occupied with and without tag, free U, alerts. | Live, refreshed every few seconds |
| Dashboard Wall | Every room on one screen for an ops-room monitor. Read-only by construction, with a scrolling rack-door event feed and an audible alert that loops until someone acknowledges it on that screen. | Live, refreshed every few seconds |
Dashboard Wall: every room on one read-only screen for the ops desk. RACK-13 shows red while its door is open; the Recent Rack Events feed lists each door open, door closed and device-returned event with its timestamp.
Rack Elevation: Rack Controller active, all strips connected, door open. Six U-SENSE tagged devices sensed in U1 to U6, 36 U free. Reserve a U-span form at the top.
Every U-slot carries one of five states
Colour-coded the same way on every view and on the rack's own LEDs.
- Empty. Nothing registered, nothing sensed.
- Allocated. Registered to this U, not yet sensed.
- In place. Sensed where the register expects it.
- Alert. A different tag sensed here; swap pending approval.
- Removed. Tag gone, nothing sensed.
- Reserved. U-span held for an incoming device.
Audit-ready movement history per device
Pull a timestamped trail of every rack and U-slot a device has occupied, who moved it, and how it was confirmed: strip telemetry, handheld scan, manual entry or movement approval. Export to Excel, PDF or CSV.
Asset lifecycle, timeline view: strip-sourced events (placed, departed, relocated, relocation rejected) sit on the same trail as handheld verifications and photo evidence. 103 audit events on this one device, filterable by date.
Same device, grid view: date, event type, description, user and location per row. Export to Excel, PDF or CSV for the auditor.
REFLECTA U-SENSE tags and in-rack sensing
A U-SENSE tag is a passive, battery-free sensing tag fixed to the device's front face, read only by the sensing cell directly in front of it. Its UID is also printed on the tag as a QR code, so a technician registers it with one handheld scan. A U-Rack Strip mounted inside the rack carries six sensing cells, one per U-position, and reads whichever tag sits in front of each cell on every sweep. Strips daisy-chain to one Rack Controller per rack, up to eight strips, so one controller covers up to 48 U-positions, enough for a 42U rack. Hardware detail on the REFLECTA U-SENSE product page.
- Continuous presence. The controller sweeps every 2 seconds by default and sends a heartbeat every 5 minutes. A change at any U is reported within one sweep. A tag that stops answering for three sweeps (about 6 seconds) raises a departure event.
- Arrival and departure events. Each is pushed to the web console as it happens, and sets a Departed badge on the asset until it is sensed or verified again.
- Swap detection with approval. If the strip senses a different device in a slot the register says belongs to someone else, the slot turns orange, the rack's LEDs show orange on that span, and the change waits in Pending Relocations for an admin to approve or reject. Placing a device into a genuinely empty slot is accepted automatically.
- One asset, many tags. A device can carry a U-SENSE tag for in-rack sensing and a UHF RFID tag for gate and dock detection at the same time. Scan either and VigiStock resolves the same asset and shows the other tag's value.
- Reservations. Hold a U-span for a device that has not arrived yet ("Incoming Dell R740, PO 4471"). The whole span renders purple on every view and the rack LEDs show purple until the device lands, then the reservation clears itself.
- LED guidance at the rack face. The server publishes the plan; the controller combines it with what it senses and lights each U: green in place, purple reserved, orange swapped, fast red expected-but-missing, off empty. The controller never waits for the server to light a pixel and never shows a colour it cannot back with a measurement.
- Hardware self-reporting. Each read carries a 0 to 100 read-quality score. A dead sensing cell is reported as a hardware fault, never as an empty slot.
- Works through a network drop. The controller keeps sensing and lighting from what it measures. When the link returns the server replays its plan and the console catches up.
The sensing path: tag to screen
Readers, Rack Controllers and the Reader Registry
VigiStock treats three kinds of reader as first-class devices, all managed from one Reader Registry page.
| Reader type | Where | What it does in VigiStock |
|---|
| Rack Controller | One per rack, networked, encrypted link | Streams U-slot telemetry, door events, strip and cell health. Receives the LED plan and Verify Now commands. |
| Portal or fixed UHF RFID reader | Facility gates, dock doors, corridors | Posts gate events. Gate rules flag unauthorised movement and raise a gate-violation webhook. |
| Handheld UHF RFID reader | With the technician, paired to the Android app | Bulk scan, cycle counts, U-slot verify mode. Licensed per reader with remote revocation. |
- Auto-discovery. The first message from any reader creates it in the registry as Unregistered with first-seen and last-seen times. An admin adopts it with a name, type and location. In the default soft mode an unknown reader's events are accepted and flagged in the audit log; in hard mode they are rejected.
- Liveness. Every reader shows Online, Idle, Offline or Never from its last-seen time. A rack controller that drops off the network without signing off is marked offline within seconds, not at the next heartbeat, so a pulled cable is visible immediately.
- Strip and cell health. A strip going dark fires a strip-link-lost webhook and an optional email immediately, and Rack Elevation overlays the affected U-range.
- Install-time calibration. The registry stores, per rack, which strip position maps to which U-range, so chain wiring order never has to match physical order.
- Security. Encrypted end to end from the rack to the server, every controller authenticated by its own device identity, every message tamper-evident. Protocol details are disclosed under NDA during the project security review.
- Alerts out of the box. Rack door opened and closed, strip link lost and restored, asset placed, swap detected, swap approved, swap rejected. Each to a signed webhook, an email subscription, or both, chosen per event type.
Mobile workflows in the data centre
The VigiStock Android app, with a paired handheld UHF RFID reader or the phone camera for QR, covers what the strips do not: racks without controllers, devices in transit, and audits that need a human signature.
- Rack-aware location assignment. Assigning a device to a rack opens a U-slot picker listing U1 to U42 with Free or Occupied by each slot. An occupied slot cannot be chosen, so two devices can never be booked into one U.
- U-Slot Verify Mode. At a U-slot during a cycle count, the app drops the handheld's RFID transmit power so only the tag directly in front answers, confirms the expected device, then restores power. It learns the right power per rack. Outcomes map to Found, Relocated or Missing.
- Tag registration by scan. Every U-SENSE and UHF RFID tag carries its own ID as a printed QR code. One scan registers it to the asset with the right identifier type.
- Audit sessions with evidence. Per-item status, watermarked photo evidence and GPS, feeding the per-asset compliance evidence PDF.
- Offline first, push before pull. Scans queue locally and sync when the network returns. The app pushes its own changes before pulling server state, so a rack walk done offline is never overwritten.
- Licensed readers, revocable remotely. Each handheld is activated with a licence file and checks in on every sync. A lost or reassigned reader is revoked from the web and stops connecting at its next sync.
Layer 6: guided operations and extended sensing
Once the rack senses itself, the next step is to let it direct the work. Layer 6 turns the live plan into guidance for the technician and extends sensing beyond presence.
| Capability | What it does |
|---|
| U-span reservations | Reserve U-positions for incoming hardware against a PO. Purple on every view and on the rack LEDs until the device is sensed in place, then cleared automatically. |
| LED guidance | The rack face shows the technician where to go and whether the placement matches the plan: green, purple, orange, fast red. Works without the network. |
| Guided MAC with server lifts | Convalexa supplies server lifts and rack-handling equipment, configured to your racks and aisles. Reserve the span, lift the device, place it, and the slot confirms itself green. The lift is itself a tagged asset, read at the gate when it leaves the hall. |
| U-Slot Verify on the handheld | Low-power single-slot confirmation for racks without strips, with the same Found, Relocated, Missing outcomes. |
| Extended sensing | Environmental smart tags, 3D room views and racks above 48U are scoped per site on the same platform. Ask for the configuration that fits your hall. |
Spec sheet
| Tag | REFLECTA U-SENSE, passive, battery-free, UID printed as QR |
| Strip | U-Rack Strip, 6 sensing cells, one per U-position |
| Controller | One per rack, up to 8 strips daisy-chained, 48 U-positions, networked |
| Transport | Proprietary encrypted, authenticated link from rack to server; details under NDA |
| Sweep and heartbeat | 2 s sweep, 5 min heartbeat, departure after 3 missed sweeps (about 6 s), configurable |
| Server | Single-tenant per install, own database, on-premises or hosted in India |
| Web views | Rack Elevation, Room Layout, Row View, Dashboard Wall, asset trace report |
| Mobile | Android app, handheld UHF RFID or camera QR, offline sync |
| Other identifiers | UHF RFID (EPC), QR, barcode on the same asset |
| Alerts | Signed webhook and email per event type |
| Integrations | Tally, Zoho Books, Odoo, Active Directory sign-in |
Who it is for
Colocation and enterprise data centres, BFSI server rooms with regulatory asset-traceability requirements, IT asset managers who must prove rack-level location history at audit time, and operators of new halls in India who can specify U-Rack Strips in the rack bill of materials before the hall opens. For the full requirements guide, compliance mapping and rollout plan, see Data Centre Asset Tracking with RFID & QR.
Frequently asked questions
Yes. The Rack Controller keeps sensing and lighting its LEDs from what it measures. When the link returns the server replays its plan and the console catches up. Nothing is invented while offline.
Yes, for a real-time view. Only a rack fitted with U-Rack Strips reports every U-position live. A rack without strips is still tracked in VigiStock by handheld UHF RFID or QR scans and appears on the same Rack Elevation, Room Layout and Row View, but it shows the state at the last scan, not the state now, so it needs a periodic manual tag-scanning session to stay current. Fit strips rack by rack as each rack's need for live sensing demands.
Yes. Scan either tag and VigiStock resolves the same asset record and shows the other tag's value. U-SENSE covers the rack; UHF RFID covers the dock and the gate.
The slot turns orange on screen and on the rack LEDs, an alert goes out by webhook or email, and an admin approves or rejects the change from Rack Elevation's Pending Relocations panel. Placing a device into a genuinely empty slot is accepted automatically.
The U-Rack Strip reports sensing-cell health separately from tag presence. A failed cell raises a hardware alert and is never shown as an empty U, so a hardware fault cannot masquerade as a missing server.
Yes. Every link from the Rack Controller to the VigiStock server is encrypted, each controller is authenticated by its own device identity, and messages are tamper-evident so gaps and replays are detected. The transport and protocol design is proprietary; details are shared under NDA during a project security review.
U-SENSE is a Convalexa solution with two halves. The hardware half is REFLECTA U-SENSE: U-SENSE tags on the assets, U-Rack Strips and a Rack Controller installed in the rack. The software half is the U-SENSE application layer inside VigiStock that the hardware connects to. It is not a separate platform: the same asset register, location tree, audit trail, Android app and evidence pack are used whether an asset is sensed by a strip, scanned by a handheld or read at a gate.
On your premises or on a dedicated hosted instance in India. Each install is single-tenant with its own database. There is no shared cloud dependency for in-rack sensing.
See your own rack on the screen
Book a 30-minute demo, or request a site assessment for a pilot rack. WhatsApp, or email us.
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