What problem does it solve? Integration tests for Modbus clients need a disposable, controllable Modbus device without real hardware. This Skill starts an isolated Modbus TCP/RTU simulator, waits for readiness, seeds register fixtures, reads state for assertions, and cleans up the process safely. ## Core Features & Use Cases - Owned-process lifecycle: Launch the simulator on replaceable high ports, wait for the MODBUS_SIMULATOR_READY signal, and terminate only the process you started. - Fixture and assertion control: Write coils and registers (including typed encodings like FloatBE or raw hex bytes), read ranges for assertions, reset state, and page through cursor-based communication logs. - Use Case: While testing a PLC integration client, start the simulator on ports 15000/15020, write holding-register fixtures with the control helper, run the client test, then collect logs and shut the simulator down. ## Quick Start Start the Modbus simulator on ports 15000 and 15020, wait for readiness, then write test fixture values to the holding registers before running my client tests.
