Simulate Modbus GPRS gateways without real hardware
Standalone Java application that emulates a GPRS modem gateway bridging Modbus TCP/serial communications for testing and integration.
What it is
Modbus Modem Simulator (Single Port) is a desktop simulator for validating Modbus GPRS client services before deployment. It accepts inbound TCP connections (simulating remote Modbus meters calling home via GPRS), bridges the traffic to a serial port (RS-485 or RS-232), and exchanges Modbus RTU frames with physical or simulated Modbus devices. Run it in database-driven mode to auto-discover controllers and devices from your deployment database, or standalone mode with command-line arguments for quick ad-hoc testing. Built-in modem disconnection cycles (10-minute intervals with 30-second recovery pauses) let you stress-test client resilience without manual intervention.
Key benefits
De-risk GPRS deployments
Test your Modbus GPRS client service against a controlled, predictable gateway before field rollout. No external modem hardware needed.
Accelerate integration testing
Run in database-driven mode to automatically load your real controller and device configurations; skip manual test setup. Or use standalone mode for quick single-device validation.
Reproduce modem behavior
Built-in 10-minute disconnect/reconnect cycles simulate real-world modem faults and network recovery, allowing you to verify client reconnection logic without waiting for production incidents.
Serial port transparency
Single physical COM port (configurable: 9600 baud, 8 data bits, 1 stop bit, no parity) acts as a gateway between TCP clients and Modbus slave devices; works with real meters or Modbus simulators on the same serial bus.
Capabilities
- Dual-mode operation: database-driven (reads active controllers and devices from platform database) or standalone (command-line parameters)
- TCP listener on a configurable port (configurable) for inbound GPRS client connections
- Modbus RTU frame bridging over single serial port (a serial port default, configurable)
- Thread-safe modem/client matching: waits for paired TCP and serial connections before starting communication
- Automatic 10-minute modem disconnection/reconnection cycles to test client resilience
- Configurable logging via platform database (configurable logging with rolling file output, size/backup limits, severity levels)
- For use within your WizIIOT deployment pipeline (license file required)
- Low-level serial port diagnostics and frame logging to aid protocol troubleshooting