Embedded Systems Development
Field-Layer Intelligence
KEANT Technologies' embedded systems engineering division delivers the firmware, communication hardware, and protocol stacks that bridge physical field devices with central monitoring platforms. This layer operates in real time — translating raw electrical signals and controller registers into structured, platform-consumable telemetry, while propagating control commands back to physical equipment with deterministic reliability.
1. Overview
Our embedded systems capability is purpose-built for industrial and infrastructure environments where reliability, real-time responsiveness, and protocol diversity are non-negotiable. We design, manufacture, and commission Edge Gateway Units (EGUs) — ruggedised embedded controllers that interface directly with field equipment, perform local signal processing, and maintain continuous uplink to central management platforms.
2. Hardware Architecture
Each field unit is interfaced through a dedicated Edge Gateway Unit (EGU) developed and supplied by KEANT Technologies. The EGU is a ruggedised embedded controller mounted directly in the equipment electrical panel, performing the following hardware functions:
| Hardware Function | Technical Detail |
|---|---|
| Signal Acquisition | Discrete I/O modules capture digital signals from equipment PCBs — running direction relays, open/close contacts, overload switches, emergency stop inputs, brake status, encoder outputs, and sensor inputs. |
| Protocol Interface | RS-485/RS-232 serial ports for Modbus RTU communication with drive controllers. Ethernet port for Modbus TCP, BACnet/IP, or proprietary IP protocols. CAN bus interface for high-speed intra-panel communication on modern installations. |
| Onboard Processing | ARM Cortex-M class microcontroller running a real-time operating system (RTOS). Handles signal conditioning, de-bouncing, watchdog supervision, local alarm latching, and command execution within deterministic timing constraints (< 50 ms response latency). |
| Connectivity | LAN/Wi-Fi uplink to operations network for forwarding telemetry to the central platform. Cellular 4G failover module ensures uninterrupted data transmission during primary network faults — critical for emergency escalation signals. |
| Power Management | Redundant 24V DC power rail with UPS-backed supply ensures EGU remains operational during mains failure, preserving emergency communication and fault logging integrity. |
3. Firmware Engineering
Our firmware engineering practice covers the full embedded software stack — from bare-metal RTOS configuration through to application-layer protocol clients and OTA update pipelines:
RTOS & Scheduling
- FreeRTOS (or equivalent) task scheduler with priority-based preemption
- Dedicated tasks for signal polling, protocol transaction handling, event queue management, telemetry packaging, and OTA update supervision
- Watchdog timer enforces firmware self-recovery on deadlock or stack overflow
- Non-volatile fault log stored in onboard Flash — survives power cycles for post-mortem analysis
Signal Processing
- Hardware debounce filters on discrete I/O lines (configurable 5–50 ms window)
- Encoder pulse counting for position tracking with rollover protection
- ADC sampling with moving average filter for accurate load and sensor detection
- Threshold-based alarm generation with configurable hysteresis to prevent alert flapping
Communication Stack
- Modbus RTU master polling field device slave registers at configurable intervals (100 ms – 1 s)
- MQTT client publishing structured JSON telemetry payloads over TLS 1.2
- Command subscription channel: central platform pushes control actions via MQTT with QoS 1 delivery guarantee
- Heartbeat mechanism: EGU publishes health beacon every 10 s; absence triggers offline alert within 30 s
OTA & Diagnostics
- Secure OTA firmware update over HTTPS with SHA-256 integrity verification and rollback on failed boot
- Remote diagnostic shell (restricted, authenticated) for signal-level debugging without physical site visit
- Self-test routine on power-up validates I/O continuity, memory integrity, and network reachability
- Onboard LED indicators and buzzer for field technician diagnostics during installation and commissioning
4. Device Integration Model
Our integration framework supports a spectrum of field device types — from fully networked intelligent controllers to simple dry-contact legacy equipment — within a single unified management platform:
| Integration Category | Approach & Capability |
|---|---|
| Fully Integrated Devices | Full bidirectional integration via EGU. All status signals are polled and forwarded in real time. Control commands are transmitted from the central platform through the EGU to the device controller, with acknowledgement feedback confirming execution. |
| Status-Only Devices | Monitoring via dry-contact I/O (Running, Fault, Out-of-Service). These units are tracked on dedicated summary screens with offline and fault indication, without bidirectional command capability. |
| Variable-Speed Drive Equipment | Read/write integration supporting direction signals, speed mode control, start/stop commands, and detailed fault category registers from the drive controller. Emergency stop inputs are wired to fail-safe hardware contacts, bypassing software for guaranteed response. |
| Audio & Broadcast Interface | EGU at designated zones interfaces with PA or broadcast amplifiers via serial or relay contacts. The central platform encodes predefined messages into command packets dispatched to the EGU which triggers zone-specific playback through the onboard audio driver. |
5. Quality, Compliance & Safety
Our embedded systems engineering practice operates to rigorous quality and safety standards. Every EGU product undergoes structured validation before site deployment:
Safety Standards & Compliance
- Signal mapping and fault classification aligned to relevant EN and IEC safety standards for the target equipment category
- Emergency signal handling and control mode compliance with applicable safety circuit requirements
- Fail-safe design: loss of EGU power or communication does not affect equipment mechanical safety circuits
- Safety-critical command channels isolated on dedicated hardware lines — not routable through general-purpose software
Testing & Validation
- Hardware-in-the-Loop (HIL) test bench simulates full field signal set for firmware validation before site deployment
- Protocol conformance testing: Modbus PDU verification against IEC 61158 reference stack
- EMC pre-compliance screening tested against IEC 61000 radiated and conducted emissions limits
- Accelerated life testing of I/O modules at 85°C / 85% RH for 500 hours validating reliability in harsh plant environments