knxultimate/src/protocol/cEMI/ControlField.ts

KNX IP protocol implementation for Node. This is the ENGINE of Node-Red KNX-Ultimate node.

import { KNXAddressType } from '../KNXAddress'

export enum FrameType {
	type0 = 0,
	type1 = 1,
}

export enum OnOff {
	off = 0,
	on = 1,
}

export enum Priority {
	Prio0 = 0,
	Prio1 = 1,
	Prio2 = 2,
	Prio3 = 3,
}

const CONTROL_LENGTH = 2

export default class ControlField {
	private control1: number

	private control2: number

	public length: number

	constructor(
		control1: number = ControlField.DEFAULT_CONTROL1,
		control2: number = ControlField.DEFAULT_CONTROL2,
	) {
		this.control1 = control1
		this.control2 = control2
		this.length = CONTROL_LENGTH
	}

	set frameType(frameType: FrameType) {
		this.control1 = (this.control1 & 0x7f) | (Number(frameType) << 7)
	}

	get frameType(): FrameType {
		return (this.control1 & 0x80) >> 7
	}

	set repeat(repeat: OnOff) {
		this.control1 = (this.control1 & 0xdf) | (Number(repeat) << 5)
	}

	get repeat(): OnOff {
		return (this.control1 & 0x20) >> 5
	}

	set broadcast(broadcast: OnOff) {
		this.control1 = (this.control1 & 0xef) | (Number(broadcast) << 4)
	}

	get broadcast(): OnOff {
		return (this.control1 & 0x10) >> 4
	}

	set priority(priority: Priority) {
		this.control1 = (this.control1 & 0xf3) | (Number(priority) << 2)
	}

	get priority(): Priority {
		return (this.control1 & 0x0c) >> 2
	}

	set ack(ack: OnOff) {
		this.control1 = (this.control1 & 0xfd) | (Number(ack) << 1)
	}

	get ack(): OnOff {
		return (this.control1 & 0x02) >> 1
	}

	set error(error: OnOff) {
		this.control1 = (this.control1 & 0xfe) | Number(error)
	}

	get error(): OnOff {
		return this.control1 & 0x01
	}

	set addressType(type: KNXAddressType) {
		this.control2 = (this.control2 & 0x7f) | (Number(type) << 7)
	}

	get addressType(): KNXAddressType {
		return (this.control2 & 0x80) >> 7
	}

	set hopCount(hopCount: number) {
		if (isNaN(hopCount) || (hopCount < 0 && hopCount > 7)) {
			throw new Error('Invalid hop count')
		}
		this.control2 = (this.control2 & 0x8f) | (Number(hopCount) << 4)
	}

	get hopCount(): number {
		return (this.control2 & 0x70) >> 4
	}

	set frameFormat(format: number) {
		if (isNaN(format) || (format < 0 && format > 15)) {
			throw new Error('Invalid frame format')
		}
		this.control2 = (this.control2 & 0xf0) | Number(format)
	}

	get frameFormat(): number {
		return this.control2 & 0xf
	}

	static get DEFAULT_CONTROL1(): number {
		return 0xbe
	}

	static get DEFAULT_CONTROL2(): number {
		return 0xe0
	}

	static createFromBuffer(buffer: Buffer, offset: number = 0): ControlField {
		if (offset + CONTROL_LENGTH >= buffer.length) {
			throw new Error(
				`offset ${offset} out of buffer range ${buffer.length}`,
			)
		}
		const control1 = buffer.readUInt8(offset++)
		const control2 = buffer.readUInt8(offset)
		return new ControlField(control1, control2)
	}

	toBuffer(): Buffer {
		const buffer = Buffer.alloc(this.length)
		buffer.writeUInt8(this.control1, 0)
		buffer.writeUInt8(this.control2, 1)
		return buffer
	}
}