ModBus read for Noark Ex9EM 1P 1M 80A MO MT

noark-ex9em.js

#!/usr/bin/env node

/*
 * ModBus read for Noark Ex9EM 1P 1M 80A MO MT Electric Meter
 * https://www.noark.com.hr/en/products/107281
 */

////////////////
// 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 = 2
////////////////////
// END CONFIGURATION
////////////////////

const ModbusRTU = require('modbus-serial')
// 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(250)

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

const getMetersValue = async (meters) => {
    try{
        // get value of all meters
        for(let meter of meters) {
            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
        setImmediate(() => {
            getMetersValue(metersIdList)
        })
    }
}

const getMeterValue = async (id) => {
    try {
        // set ID of slave
        await client.setID(id);
        // read the registers starting at address 0 (first register)
        let val = await client.readHoldingRegisters(0x00, 11);
        

        const v = val.data[0] / 100
        const i = val.data[1] / 100
        const phase = val.data[2] / 100
        const p = val.data[3]
        const pr = val.data[4]
        const pa = val.data[5]
        const eff = val.data[6] / 10
        const total_p = (val.data[7] * (1 << 16) + val.data[8]) / 100
        const total_pr = (val.data[9] * (1 << 16) + val.data[10]) / 100

        console.log('====================')
        console.log(`Electric Meter ${id}`)
        console.log(`V = ${p} V`)
        console.log(`I = ${i} A`)
        console.log(`phase = ${phase} Hz`)
        console.log(`P = ${p} W`)
        console.log(`Pr = ${pr} VAr`)
        console.log(`Pa = ${pa} VA`)
        console.log(`Power factor = ${eff} %`)
        console.log(`total a = ${total_p} kWh`)
        console.log(`total r = ${total_pr} kVArh`)

    } catch (e) {
        return -1
    }
}

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


// start get value
getMetersValue(metersIdList);

package.json

{
  "name": "test-modbus",
  "version": "1.0.0",
  "description": "",
  "author": "Geno Roupsky",
  "license": "ISC",
  "dependencies": {
    "modbus-serial": "^8.0.1"
  }
}