lxi-tools (JavaScript)

JavaScript port of lxi-tools for controlling LXI compatible instruments (oscilloscopes, power supplies, spectrum analyzers, etc.).

Pure Node.js implementation with zero external dependencies. Supports VXI-11 and RAW/TCP protocols.

Features

• Device Discovery — VXI-11 UDP broadcast + mDNS/DNS-SD
• SCPI Commands — one-shot or persistent session mode
• Screenshot Capture — 24 built-in instrument plugins with auto-detection
• Benchmarking — measure instrument request/response rate
• Low-level Control — full connect / send / receive / disconnect API

Installation

# Import directly (within the project)
import { lxi, discovery, SCPI } from './js/index.js';

# Or install as a local package
npm install ./js

Requires Node.js >= 18 (uses node:net, node:dgram, node:os)

Quick Start

import { discovery, SCPI } from "./js/index.js";

// Discover LXI devices on the local network
const devices = await discovery.discover({ timeout: 2000 });
console.log(devices);
// [{ address: '10.0.0.42',
//    id: 'RIGOL TECHNOLOGIES,DS1054Z,...' }]

// Send a SCPI command
const id = await SCPI.scpi("10.0.0.42", {
	command: "*IDN?",
});
console.log(id);
// 'RIGOL TECHNOLOGIES,DS1054Z,...,00.04.04.SP3'

API Reference

Discovery

discovery.discover(options?)

Search the network for LXI devices.

import { discovery } from "lxi-tools";

// VXI-11 broadcast discovery (default)
const devices = await discovery.discover({
	timeout: 1000,
});

// mDNS/DNS-SD discovery
const services = await discovery.discover({
	mdns: true,
	timeout: 5000,
});

| Parameter | Type | Default | Description | | --------------------- | ---------- | ------------- | -------------- | | options.mdns | boolean | false | Use mDNS | | options.timeout | number | 1000/5000 | ms | | options.onDevice | function | — | Per-device cb | | options.onService | function | — | Per-service cb | | options.onBroadcast | function | — | Per-iface cb |

Returns: Promise<Array<{ address, id }>> or Promise<Array<{ address, id, service, port }>>

SCPI Commands

SCPI.scpi(address, options)

Send a SCPI command and optionally receive a response. The connection is opened and closed automatically.

import { SCPI } from "lxi-tools";

// Query commands (containing '?') return a string
const id = await SCPI.scpi("10.0.0.42", {
	command: "*IDN?",
});

// Set commands return null
await SCPI.scpi("10.0.0.42", { command: "*RST" });

// Using RAW/TCP protocol
await SCPI.scpi("10.0.0.42", {
	command: "*IDN?",
	protocol: "RAW",
	port: 5025,
	timeout: 5000,
});

| Parameter | Type | Default | Description | | ------------------ | -------- | ------------ | ----------- | | address | string | required | IP address | | options.command | string | required | SCPI cmd | | options.port | number | 0 (auto) | Port | | options.timeout | number | 3000 | ms | | options.protocol | string | 'VXI11' | Protocol |

Returns: Promise<string | null>

SCPI.scpiOnDevice(device, command, timeout?)

Send a SCPI command on an existing connection. Useful for multi-command sessions.

import { lxi, SCPI } from "lxi-tools";

const dev = await lxi.connect("10.0.0.42");
const id = await SCPI.scpiOnDevice(dev, "*IDN?");
await SCPI.scpiOnDevice(dev, ":CHAN1:DISP ON");
await lxi.disconnect(dev);

SCPI.scpiRaw(device, command, timeout?)

Send a raw command and return a Buffer. No newline is appended and no string processing is done.

Low-level Connection Control

lxi.connect(address, port?, name?, timeout?, protocol?)

Open a connection to an instrument. Returns a device handle (integer).

import { lxi } from "lxi-tools";

const dev = await lxi.connect("10.0.0.42", 0, "inst0", 3000, "VXI11");

| Parameter | Type | Default | Description | | ---------- | -------- | ------------ | ------------------------- | | address | string | required | IP address | | port | number | 0 | Auto: VXI11→111, RAW→5025 | | name | string | 'inst0' | VXI-11 device name | | timeout | number | 3000 | ms | | protocol | string | 'VXI11' | 'VXI11'/'RAW' |

Returns: Promise<number> — device handle

lxi.send(device, command, timeout?)

Send data to a connected instrument.

Returns: Promise<number> — bytes sent

lxi.receive(device, maxLength?, timeout?)

Receive data from a connected instrument.

Returns: Promise<Buffer> — response data

lxi.disconnect(device)

Close the connection.

lxi.Protocol

Protocol constants: lxi.Protocol.VXI11, lxi.Protocol.RAW

Screenshot

Screenshot.screenshot(address, options?)

Capture a screenshot from an instrument. Supports auto-detection of the instrument model.

import fs from "node:fs";
import { Screenshot } from "lxi-tools";

const img = await Screenshot.screenshot("10.0.0.42");
fs.writeFileSync(`screenshot.${img.format}`, img.data);

// Specify a plugin explicitly
const img2 = await Screenshot.screenshot("10.0.0.42", {
	plugin: "rigol-1000z",
	timeout: 15000,
});

| Parameter | Type | Default | Description | | ----------------- | -------- | ------------ | ----------- | | address | string | required | IP address | | options.plugin | string | auto | Plugin name | | options.timeout | number | 10000 | ms |

Returns: Promise<{ data: Buffer, format: string, plugin: string }>

Screenshot.listPlugins()

List all available screenshot plugins.

import { Screenshot } from "lxi-tools";

const plugins = Screenshot.listPlugins();
// [{ name: 'rigol-1000z',
//    description: 'Rigol DS1000Z/MSO1000Z' }, ...]

Screenshot.detectPlugin(address, timeout?)

Auto-detect the plugin from the *IDN? response.

Returns: Promise<string | null> — plugin name

Supported Instruments

| Plugin | Instrument | Fmt | | ------------------ | ------------------------- | --- | | keysight-dmm | Keysight 34xxxA DMM | BMP | | keysight-dso | Keysight MSO/DSO6000A | BMP | | keysight-ivx | Keysight InfiniiVision X | BMP | | keysight-psa | Keysight E44xxA PSA | GIF | | keysight-pxa | Keysight N90xxA PXA | PNG | | lecroy-wp | LeCroy WavePro/WaveRunner | PNG | | rigol-1000z | Rigol DS1000Z / MSO1000Z | PNG | | rigol-2000 | Rigol DS/MSO 2000–8000 | BMP | | rigol-dg | Rigol DG1000Z / DG4000 | BMP | | rigol-dl3000 | Rigol DL3000 | BMP | | rigol-dm3068 | Rigol DM3068 | BMP | | rigol-dp800 | Rigol DP800 | BMP | | rigol-dsa | Rigol DSA700 / DSA800 | BMP | | rs-fsv | Rohde & Schwarz FSV | PNG | | rs-hmo-rtb | Rohde & Schwarz HMO/RTB | PNG | | rs-ng | Rohde & Schwarz NGM/NGL | PNG | | rs-rth | Rohde & Schwarz RTH | PNG | | siglent-sdg | Siglent SDG | BMP | | siglent-sdm3000 | Siglent SDM3000 | BMP | | siglent-sds | Siglent SDS1000/SDS2000 | BMP | | siglent-ssa3000x | Siglent SSA3000X | BMP | | tektronix-2000 | Tektronix DPO/MSO 2000 | PNG | | tektronix-3000 | Tektronix TDS3000 | BMP | | tektronix-mso-5 | Tektronix MSO5000 | PNG |

Benchmark

Benchmark.benchmark(address, options?)

Measure instrument response rate by repeatedly sending *IDN? requests.

import { Benchmark } from "lxi-tools";

const result = await Benchmark.benchmark("10.0.0.42", {
	count: 200,
	timeout: 5000,
	onProgress: (n) => {
		process.stdout.write(`\r${n}/200`);
	},
});
console.log(`${result.requestsPerSecond.toFixed(1)} req/s`);

| Parameter | Type | Default | Description | | -------------------- | ---------- | ------------ | ----------- | | address | string | required | IP address | | options.port | number | 0 | Port | | options.timeout | number | 3000 | ms | | options.protocol | string | 'VXI11' | Protocol | | options.count | number | 100 | Requests | | options.onProgress | function | — | Callback |

Returns: Promise<{ requestsPerSecond, count, elapsed }>

Advanced API

Available for low-level or custom usage:

import { vxi11, rpc } from "lxi-tools";

• vxi11.vxi11Connect(host, port, name, timeout) — create a VXI-11 session directly
• vxi11.getVxi11Port(host, timeout) — query the VXI-11 port via portmapper
• rpc.XdrWriter / rpc.XdrReader — XDR encoding/decoding utilities

Project Structure

js/
├── index.js          # Entry point, unified exports
├── package.json
├── README.md
└── lib/
    ├── rpc.js        # XDR codec + ONC-RPC protocol
    ├── vxi11.js      # VXI-11 protocol
    ├── lxi.js        # Core connection (VXI11 + RAW)
    ├── discover.js   # Device discovery
    ├── scpi.js       # SCPI command I/O
    ├── benchmark.js  # Performance benchmark
    └── screenshot.js # Screenshot (24 plugins)

Mapping to the C Version

| JS Module | C Source | Purpose | | ------------------- | ------------------------------ | ----------------- | | lib/rpc.js | liblxi | VXI-11/RPC | | lib/vxi11.js | liblxi | VXI-11/RPC | | lib/lxi.js | liblxi API | connect/send/recv | | lib/discover.js | discover.c | Discovery | | lib/scpi.js | scpi.c | SCPI commands | | lib/benchmark.js | benchmark.c | Benchmark | | lib/screenshot.js | screenshot.c + plugins/*.c | Screenshot |

Acknowledgments

This JavaScript port was developed with the decisive contribution of Claude Opus (Anthropic) serving as the AI pair-programmer. Opus performed the full C → JavaScript translation, designed the zero-dependency architecture, implemented the ONC-RPC / XDR / VXI-11 protocol stack, authored all 24 screenshot plugins, and wrote the test suite and documentation.

License

BSD-3-Clause — Ported from lxi-tools by Martin Lund.