Safety System Products
Production Test Cabinet
To take SSP's Simplifier Gateway from certification into stable serial production, I designed the end-of-electronics production test that screens every unit before final assembly — catching hardware and communication faults immediately after the six-PCB assembly is formed, before it enters its mechanical enclosure.
Project Brief
- Type
- End-of-line manufacturing test
- Platform
- Beckhoff TwinCAT 3 / CX7080
- Orchestration
- ASP.NET backend + Vue 3 frontend
- Integration
- Company ERP system
1.What the Test Covers
End-to-End Test Sequence
The test follows a strict 80+ step automated sequence. Each unit begins with an ERP scan to retrieve its serial number, MAC address, and model, then powers on and flashes target firmware before interface verification begins.
Each interface is exercised in sequence — digital I/O loopback, CAN loopback, voltage checks, fieldbus, buttons, LEDs, and display. A step must pass before the next begins, and every step carries an explicit timeout.
Real-World Fault Detection
The test has caught manufacturing defects that visual inspection missed. Because it exercises every electrical path and interface, it reveals problems that only appear when the device is actually running.
- Connectors not soldered properly
- Buttons or LEDs non-functional
- Internal voltage measurements out of acceptable range
ERP Traceability
Every unit leaves a complete digital trail in the ERP system, supporting quality audits, customer traceability requests, and long-term reliability analysis.
- Serial numbers, MAC addresses, and model numbers
- Test timestamps and operator ID
- Measured values and flashed firmware version
Cycle Time & Failure Handling
A full test cycle takes 5 to 6 minutes per unit. The test distinguishes between recoverable and irrecoverable failures: recoverable faults are handled gracefully and the sequence continues; irrecoverable failures trigger a hard stop and generate a failure report.
On pass, a PDF report is generated alongside the ERP write and can be sent to the customer on request.
2.System Architecture
Hardware
The rig is a Beckhoff TwinCAT 3 test cabinet built around a CX7080 embedded PC. EtherCAT terminals were selected to match the device's full I/O profile:
EL2008 (digital outputs), EL3174 (voltage measurement), EL3692 (resistance measurement), EL6751 (CAN transmit/receive, multiplexed via relays across the gateway's two CAN ports), and EL6631 (PROFINET/PROFIsafe). The rig also controls a digital power supply over RS-232.
Backend & Runtime Core
The backend runs on .NET 8 and exposes a REST API. A sequence engine manages the full test lifecycle — executing steps, handling hardware connections, generating reports, and recording final pass results.
The step layer translates commands into concrete PLC and serial actions, communicating with the Beckhoff runtime over ADS and with the device over a 460800 baud serial link. A stats manager serves as the single source of truth for in-memory measurements shared across the API and reporting layers.
Vue 3 Frontend
The operator interface follows a staged dashboard flow: connect the station, choose a test method, resolve device identity, run the sequence, then inspect results and reports. A separate Settings screen handles configuration.
State is split across five stores covering connection status, sequence progress, device statistics, settings, and report data. The frontend polls for live status and measurements through a single API service, and reports open inline rather than downloading.
