@modbus-ts/subscription

Polling subscription engine with range merge and change detection.

Installation

pnpm add @modbus-ts/subscription

Core Exports

• SubscriptionGroup
• MergedRange
• PollGroup
• SubscriptionEngine

Minimal Example

import { SubscriptionEngine } from '@modbus-ts/subscription'

const engine = new SubscriptionEngine({
  readRegisters: async ({ start, length }) => new Array(length).fill(start),
})

const unsubscribe = engine.subscribe({
  unitId: 1,
  start: 0,
  length: 4,
  interval: 500,
  callback: (registers) => console.log(registers),
})

engine.start()
unsubscribe()
engine.stop()

Behavior

• Groups subscriptions by interval
• Merges overlapping ranges per unitId
• Calls callback only when values changed

Packages

• high-level Modbus client
• shared contracts, types, and errors
• FC1/FC2/FC3/FC4/FC5/FC6/FC15/FC16 frame encode/decode for TCP/RTU/ASCII
• serial request queue with priority
• polling engine and range merge
• Node TCP transport with reconnect
• Node UDP transport
• browser WebSocket transport with reconnect
• typed Electron main/renderer bridge
• Electron IPC transport adapter
• WebSocket to TCP binary relay gateway
• register-value codec helpers
• shared async and comparison utilities