TECHNICAL SPECIFICATIONS
Interkey Brain v4.0
Industrial Programmable Logic Controller — Complete Technical Reference
Version 4.0SYSTEM OVERVIEW
Vertically Integrated PLC
Interkey Brain is a vertically integrated industrial PLC delivered as a complete cabinet solution. Controller hardware, I/O modules, power distribution, AI co-processor, and a full software stack ship together — no separate SCADA, HMI panels, or engineering workstations required.
SECTION 1
Controller Hardware
| Parameter | Specification |
|---|---|
| Main Controller | CompuLab SBC-IOT-iMX8Plus (ARM, NXP i.MX8M Plus) |
| AI Co-Processor | NVIDIA Jetson Orin Nano Super (40 TOPS AI inference) |
| Panel Display | 14" IPS, 3840×1100px, direct GPU rendering (eglfs) |
| Communication Bus | RS-485 native (half-duplex differential pair) |
| Bus Protocol | Modbus RTU, 115200 baud default (300–115200 configurable) |
| Network | Gigabit Ethernet, 802.11ac Wi-Fi (optional) |
| Operating System | Linux (Yocto/Ubuntu) |
| Brain Core Cabinet | 400mm × 600mm × 200mm (W × H × D), ~12 kg |
| Brain Pro Cabinet | 600mm × 800mm × 250mm (W × H × D), ~25 kg |
| IP Rating | IP54 (front panel), IP20 (interior — install in protected enclosure for harsh environments) |
| Mounting | DIN-rail, panel mount, or floor stand (Brain Pro) |
| Cooling | Passive (Brain Core), forced-air with thermal monitoring (Brain Pro) |
SECTION 2
I/O Module Specifications
| Module | Model | Qty | Channels | Modbus Addresses | Description |
|---|---|---|---|---|---|
| RTD Temperature | WPRTD | 4 | 64 (16/board) | 0x01–0x04 | PT100/PT1000, 3/4-wire, −200 to +500°C |
| Digital Input | WPIO-DI | 4 | 64 (16/board) | Discrete 0x00–0x3F | Pulse width measurement, timestamp tracking |
| Digital Output | WPIO-DO | 4 | 64 (16/board) | Coils 0x00–0x3F | Relay/transistor outputs |
| SSR Control | WPPWR+WPPWS | 6+24 | 24 SSR outputs | 0x07–0x0A | 25A TRIAC, 0–100% duty cycle |
| Power Supply Monitor | WPPSU | 2 | 2 units | Reg 400+ | 0–1000V, 0–100A, 0–10kW |
| Camera Ports | — | 2 | 2 cameras | Reg 500+ | RTSP/ONVIF IP camera |
Total I/O Capacity: 220 points (64 RTD + 64 DI + 64 DO + 24 SSR + 2 PSU + 2 CAM)
SECTION 3
RTD Temperature Board Detail
| Parameter | Specification |
|---|---|
| MCU | STM32F412CGUx (ARM Cortex-M4F, 100 MHz, 1MB Flash, 256KB RAM) |
| ADC | Texas Instruments ADS1220, 24-bit delta-sigma |
| System Accuracy | ±0.2°C typical, ±0.3°C maximum |
| Temperature Range | −200°C to +500°C |
| Sensor Types | PT100, PT1000, auto-detection |
| Wiring | 3-wire and 4-wire (software-selectable) |
| Channel Scan Rate | 5 Hz @ 90 SPS (high accuracy), 23 Hz @ 600 SPS (fast) |
| Data Logging | 128MB NAND flash, ~12 days continuous |
| ESD Protection | ±8 kV contact per IEC 61000-4-2 |
| Crypto | ATSHA204A (SHA-256) on every board |
| Input Voltage | 10–30V DC |
| PCB | 190.36mm × 81.75mm, 4-layer |
SECTION 4
SSR Control Board
| Parameter | Specification |
|---|---|
| Base Board MCU | STM32F412CGUx |
| Switch Module MCU | STM8S105K4T6C |
| Switching Element | 25A TRIAC solid-state relay |
| Duty Cycle Resolution | 0.01% |
| Current Monitoring | Per-channel, real-time |
| Overcurrent Protection | 15A threshold, 100ms trip |
| Overtemperature Shutdown | 85°C |
SECTION 5
Communication Bus
| Parameter | Specification |
|---|---|
| Physical Layer | RS-485 differential pair |
| Protocol | Modbus RTU |
| Baud Rates | 300–115200 |
| Max Devices | 256 per bus |
| Max Bus Length | 1200m @ 38.4 kbps |
| Transceiver | SN65HVD75DRBT (up to 20 Mbps) |
SECTION 6
Industrial Protocol Support
| Protocol | Mode | Details |
|---|---|---|
| Modbus RTU | Server + Client | RS-485, 8 function codes |
| Modbus TCP | Server + Client | MBAP header, 125 registers/read |
| MQTT | Publish + Subscribe | TLS/SSL, QoS 0/1/2 |
| OPC UA | Server + Client + Pub/Sub | Subscriptions, historian |
| SparkPlug B | Publisher | Protobuf-encoded MQTT |
| Cloud MQTT Bridge | Publisher | AWS IoT Core, Azure IoT Hub |
| MCP | Server (Server + Client roadmap 2026) | Connect Brain as an MCP endpoint for Claude Desktop, Cursor, and any custom AI agent. JSON-RPC 2.0 over port 8766 with API key authentication. |
| Webhooks | Publisher | HMAC-SHA256 signed |
SECTION 7
Backend Server
| Parameter | Specification |
|---|---|
| Language | Go, cross-compiled for ARM64 |
| API | 100+ REST endpoints, 33 route groups |
| Auth | JWT with 5 RBAC roles |
| Real-Time | WebSocket with compression |
| PLC Engine | Custom IEC 61131-3, 100ms scan cycle |
| Tag history (BadgerDB time-series) | 5-second default sampling, 7-day default retention, deadband optimization, configurable up to years |
| Audit trail (SQLite WAL) | Hash-chain immutable, NTP-synchronized, exportable, 90-day default retention configurable |
| Metrics (Prometheus) | 15-second scrape interval, 30-day local retention, remote-write compatible |
| Project versioning | Full project snapshots with diff viewer, 90-day default retention |
SECTION 8
PLC Programming
| Parameter | Specification |
|---|---|
| Structured Text | IEC 61131-3, math functions, timer FBs |
| Ladder Logic | Visual relay-style, drag-and-drop |
| Function Block Diagram | 35 block types, 7 categories |
| Sequential Function Chart | Step/transition editor |
| ISA-88 Batch Control | Master/control recipes |
SECTION 9
AI Vision & Audio
| Parameter | Specification |
|---|---|
| Platform | NVIDIA Jetson Orin Nano Super (40 TOPS) |
| Camera Support | Up to 20 cameras (RTSP/ONVIF) |
| Microphone Support | Up to 10 microphones |
| Detection | Water level, color, gauge reading, anomaly |
| Audio Analysis | FFT spectral, z-score anomaly |
| Learning | 3-phase (Learning 6h, Validation 2h, Autonomous) |
| Air-gap mode | Fully local on Jetson, zero cloud calls in autonomous phase. Bootstrap can be skipped for fully air-gapped operation. |
SECTION 10
HMI Builder
| Parameter | Specification |
|---|---|
| Widget Types | 17 types |
| Canvas | 570×900px, drag-and-drop |
| Features | Resize, z-ordering, undo/redo, snap guides |
| Templates | 5 pre-built |
| Publishing | One-click to tablet |
SECTION 11
System Requirements & Compliance
System Requirements
| Parameter | Specification |
|---|---|
| Input Power | 10–30V DC |
| Typical Power Consumption | ~120W typical (Brain Pro fully loaded) |
| Peak Power Consumption | ~280W peak (heavy AI inference + all I/O active + Jetson at full load) |
| Recommended PSU Rating | 350W minimum, 400W recommended for headroom |
| Inrush Current | <5A typical with eFuse current limiting |
| Operating Temp (I/O) | −40°C to +85°C |
| Operating Temp (Controller) | 0°C to +50°C |
| Resilience | PLC continues if backend/AI/network goes down |
| Security | JWT+RBAC, HMAC, ATSHA204A hardware auth |
Compliance Standards
| Parameter | Specification |
|---|---|
| PLC Programming | IEC 61131-3:2025 (Edition 4) — introduces OOP, Properties, Mutex/Semaphore, and UTF-8 native support. Full Brain compliance verified. |
| Temperature Sensors | IEC 60751 |
| Batch Control | ISA-88 |
| ESD Immunity | IEC 61000-4-2 |
| Fast Transient | IEC 61000-4-4 |
| Serial Bus | TIA/EIA-485-A |
| OPC UA Pub/Sub | OPC UA Part 14 |
SECTION 12
Reliability & Resilience
| Parameter | Specification |
|---|---|
| Hardware watchdog | IWDG on every I/O board, 2-second timeout, hardware-level (cannot be disabled by firmware) |
| Software watchdog | Controller-level, monitors AI service health |
| Circuit breaker | AI service isolation on consecutive failures, exponential backoff retry |
| Audit trail | SQLite WAL mode, hash-chain integrity, NTP-synchronized timestamps, exportable to JSON/CSV/PDF |
| Historian durability | BadgerDB time-series, 5s default sampling, 7-day default retention, configurable to years |
| Backup/restore | Full project snapshots: PLC code, HMI pages, alarms, recipes, plugins. Diff viewer. One-click rollback. 90-day default version retention. |
| Degraded-mode operation | PLC engine, drivers, alarm processing all continue operating independent of AI/backend/network |
| Power loss recovery | Last known state restored on power-on |
SECTION 13
Safety Architecture
| Parameter | Specification |
|---|---|
| Authorization model | 5-tier: Read / Inform / Configure / Control / Safety-Critical |
| Auto-lock | 3 Tier-3 actions in 60 seconds disables all autonomous modes; manual admin reset required |
| Emergency stop endpoint | POST /ai/emergency-stop — kills all automation instantly, notifies all operators |
| Audit trail per AI action | Every action logged with tool, arguments, tier, approver, timestamp, result; immutable |
| Approve & Remember | Operator approval can create pre-approved rule with expiration (default 90 days, configurable); rules cannot escalate above Tier 3; revocable instantly |
| Hardware E-stop | External button physically wired to hardware safety relay, independent of controller and AI; cannot be overridden by software |
| AI failure escalation | <1 second alarm via local audio + configurable channels (email, SMS, webhook) |
SECTION 14
Roadmap Compliance
Section 11 covers what's shipped today; this section covers in-progress standards.
| Standard | Description | Target |
|---|---|---|
| IEC 62443 | Industrial cybersecurity | Q4 2026 |
| IEC 61508 SIL 2 | Functional safety, Brain Core I/O | Q1 2027 |
| IEC 61508 SIL 3 | Functional safety, full cabinet | Q3 2027 |
| EU AI Act conformity | High-risk industrial AI system documentation | 2027 |
| CE marking | EU machinery directive | Q3 2026 |
| UL 508A | Listed industrial control panel | Q4 2026 |
| ATEX Zone 22 | Explosive atmospheres variant | 2028 |
See /compliance for full standards roadmap.
SECTION 15
Internationalization
Full UI localization in 9 languages: English, Spanish, French, German, Italian, Portuguese, Chinese (Simplified), Japanese, and Korean.
Version 4.0 | Interkey | For detailed board-level documentation, contact technical sales.