ModBus read for Sinotype DDS024MR Electric Meter (https://s.click.aliexpress.com/e/_eNIqlR)

sinotype-dds024mr.js

#!/usr/bin/env node

/*
 * ModBus read for Sinotype DDS024MR Electric Meter
 * https://s.click.aliexpress.com/e/_eNIqlR
 */

////////////////
// CONFIGURATION
////////////////
const DEVICE = '/dev/ttyUSB0'

// possible values 1200, 2400, 4800, 9600, default 9600
const BAUD_RATE = 9600

// possible values 'even', 'odd', 'none', default 'even'
const PARITY = 'even'

// possible values 1-247, default 1
const ADDRESS = 1
////////////////////
// END CONFIGURATION
////////////////////

const ModbusRTU = require('modbus-serial')
const ieee754 = require('ieee754')
// create an empty modbus client
const client = new ModbusRTU()
// open connection to a serial port
client.connectRTUBuffered(DEVICE, { baudRate: BAUD_RATE, parity: PARITY })
// set timeout, if slave did not reply back
client.setTimeout(500)

// list of meter's id
const metersIdList = [ADDRESS]

const getMetersValue = async (meters) => {
    try{
        // get value of all meters
        for(let meter of meters) {
            // output value to console
            console.log(`${meter}:`, await getMeterValue(meter));
            // wait 100ms before get another device
            await sleep(100)
    }
    } catch(e){
        // if error, handle them here (it should not)
        console.log(e)
    } finally {
        // after get all data from salve repeate it again
        setTimeout(() => {
            getMetersValue(metersIdList)
        }, 1000)
    }
}

const getMeterValue = async (id) => {
    try {
        // set ID of slave
        await client.setID(id)

        let val = await client.readHoldingRegisters(0x00, 0x12);
	// Baud rate - 1200, 2400, 4800 or 9600
	const baud = ieee754.read(val.buffer, 0x00<<1, false, 23, 4)
	// Parity - 0: even, 1: odd, 2: none
        const parity = ieee754.read(val.buffer, 0x02<<1, false, 23, 4)
	// Device address
        const address = ieee754.read(val.buffer, 0x08<<1, false, 23, 4)
	// Relay control - according to docs 1 is on, 2 is off, but I read only 0
        const relay = ieee754.read(val.buffer, 0x10<<1, false, 23, 4)

        val = await client.readInputRegisters(0x00, 0x38)
	// A phase voltage in Volts
        const av = ieee754.read(val.buffer, 0x00<<1, false, 23, 4)
	// B phase voltage in Volts
        const bv = ieee754.read(val.buffer, 0x02<<1, false, 23, 4)
	// C phase voltage in Volts
        const cv = ieee754.read(val.buffer, 0x04<<1, false, 23, 4)
	// A line current in Amps
        const ac = ieee754.read(val.buffer, 0x08<<1, false, 23, 4)
	// B line current in Amps
        const bc = ieee754.read(val.buffer, 0x0A<<1, false, 23, 4)
	// C line current in Amps
        const cc = ieee754.read(val.buffer, 0x0C<<1, false, 23, 4)
	// total active power in kWh
        const tot_ap = ieee754.read(val.buffer, 0x10<<1, false, 23, 4)
	// A phase active power in kWh
        const a_ap = ieee754.read(val.buffer, 0x12<<1, false, 23, 4)
	// B phase active power in kWh
        const b_ap = ieee754.read(val.buffer, 0x14<<1, false, 23, 4)
	// C phase active power in kWh
        const c_ap = ieee754.read(val.buffer, 0x16<<1, false, 23, 4)
	// total reactive power in kVAr
        const tot_rp = ieee754.read(val.buffer, 0x18<<1, false, 23, 4)
	// A phase reactive power in VAr (could be kVAr)
        const a_rp = ieee754.read(val.buffer, 0x1A<<1, false, 23, 4)
	// B phase reactive power in VAr (could be kVAr)
        const b_rp = ieee754.read(val.buffer, 0x1C<<1, false, 23, 4)
	// C phase reactive power in VAr (could be kVAr)
        const c_rp = ieee754.read(val.buffer, 0x1E<<1, false, 23, 4)
	// A phase power factor
        const apf = ieee754.read(val.buffer, 0x2A<<1, false, 23, 4)
	// B phase power factor
        const bpf = ieee754.read(val.buffer, 0x2C<<1, false, 23, 4)
	// C phase power factor
        const cpf = ieee754.read(val.buffer, 0x2E<<1, false, 23, 4)
	// frequency in Hz
        const freq = ieee754.read(val.buffer, 0x36<<1, false, 23, 4)

        val = await client.readInputRegisters(0x100, 2)
	// total active electricity power in kWh
        const tot_act = ieee754.read(val.buffer, 0x00, false, 23, 4)

        val = await client.readInputRegisters(0x400, 2)
	// total reactive electricity power in kVArh
        const tot_react = ieee754.read(val.buffer, 0x00, false, 23, 4)

        return {
            baud, parity, address, relay,
            av, bv, cv, ac, bc, cc,
            tot_ap, a_ap, b_ap, c_ap,
            tot_rp, a_rp, b_rp, c_rp,
            apf, bpf, cpf, freq,
            tot_act, tot_react
        }
    } catch(e){
        // if error return -1
        return -1
    }
}

const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms))


// start get value
getMetersValue(metersIdList)