vxi-mock-device

VXI-11 mock instrument for testing @produck/lxi-tools-node without real hardware.

Implements a TCP portmapper + VXI-11 core channel server that responds to SCPI commands via user-registered handlers.

Usage

import { MockDevice } from "@produck/vxi-mock-device";

const mock = new MockDevice({
	identity: "RIGOL TECHNOLOGIES,DS1054Z,DS1ZA000000001,00.04.04.SP3",
});

// Register custom SCPI handlers
mock.handle(":DISP:DATA?", () => {
	return fs.readFileSync("fixture.png");
});

await mock.start();
console.log(`VXI-11 on port ${mock.vxi11Port}`);

// ... run tests against 127.0.0.1 ...

await mock.stop();

API

new MockDevice(options?)

| Option | Type | Default | Description | | ---------------- | -------- | ------------------------------- | ------------------------------------- | | identity | string | 'MOCK,MockDevice,SN001,1.0.0' | *IDN? response | | maxReceiveSize | number | 0x100000 (1 MB) | VXI-11 maxRecvSize reported to client | | fragmentSize | number | 0 | RPC fragment size (0 = single) | | host | string | '127.0.0.1' | Listen address for all TCP servers |

mock.handle(command, handler)

Register a SCPI command handler (case-insensitive). Handler signature: (command: string) => string | Buffer | null | Promise<...>

mock.removeHandler(command)

Remove a previously registered handler.

mock.start(portmapperPort?, vxi11Port?)

Start the mock device. Use port 0 (default) for OS-assigned ephemeral ports.

mock.stop()

Stop the mock device and release all resources.

Properties

| Property | Description | | ---------------- | ------------------------------------------- | | portmapperPort | TCP port of the portmapper (after start) | | vxi11Port | TCP port of the VXI-11 server (after start) | | host | Listen address | | identity | Configured *IDN? string |

Multi-fragment Testing

Set fragmentSize to a small value to force multi-fragment RPC record marking — useful for regression-testing the client's multi-fragment parser:

const mock = new MockDevice({
	fragmentSize: 1024, // split replies into 1 KB fragments
});

License

MIT