nord.js

const SerialPort = require('serialport');
const fs = require('fs');


//request reset on address /?9999999
let request_init   = [ 0x2f, 0x3f, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x21, 0x0d, 0x0a ];
//select register "51"
let request_select_register_51 = [0x06, 0x30, 0x35, 0x31, 0x0d, 0x0a];
//.R1.0030().
let request_register_R1_30 = [
    0x01, 0x52, 0x31, 0x02, 0x30, 0x30, 0x33, 0x30, 0x28, 0x29, 0x03, 0x60
];

let request_register_R1_50 = [
    0x01, 0x52, 0x31, 0x02, 0x30, 0x30, 0x35, 0x30, 0x28, 0x29, 0x03, 0x66
];     	

let request_register_R1_100 = [
    0x01, 0x52, 0x31, 0x02, 0x30, 0x31, 0x30, 0x30, 0x28, 0x29, 0x03, 0x62
];     	
//select via serial number
let request_select = [ 0x2f, 0x3f, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x33, 0x21, 0x0d, 0x0a ];



//ack
let response1 = [0x2f, 0x41, 0x53, 0x0d, 0x0a];
//.P0.(18060583).a
let response2 = [0x01, 0x50, 0x30, 0x02, 0x28, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x33, 0x29, 0x03, 0x61];
//.0030(18060583).
let response3 = [0x02, 0x30, 0x30, 0x33, 0x30, 0x28, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x33, 0x29, 0x03, 00];
//.0100(0D010556).
let response4 = [0x02, 0x30, 0x31, 0x30, 0x30, 0x28, 0x30, 0x44, 0x30, 0x31, 0x30, 0x35, 0x35, 0x36, 0x29, 0x03, 0x70];
let response5 = [0x2f, 0x41, 0x53, 0x0d, 0x0a];
//.P0.(18060583).a
let response6 = [0x01, 0x50, 0x30, 0x02, 0x28, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x33, 0x29, 0x03, 0x61];
//.0050(+006511.71,+006511.71,+000000.00)..
//41 bytes
let response7 = [
    0x02, 0x30, 0x30, 0x35, 0x30, 0x28, 0x2b, 0x30, 0x30, 0x36, 0x35, 0x31, 0x31, 0x2e, 0x37, 0x31, 0x2c, 0x2b,
    0x30, 0x30, 0x36, 0x35, 0x31, 0x31, 0x2e, 0x37, 0x31, 0x2c, 0x2b, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x2e,
    0x30, 0x30, 0x29, 0x03,0x02
];

let requests = [
    request_init,
    request_select_register_51,
    request_register_R1_30,
    request_register_R1_100,
    request_select,
    request_select_register_51,
    request_register_R1_50
];

let responses = [
    response1,
    response2,
    response3,
    response4,
    response5,
    response6
];

function byteArrayEquals(arr1, arr2){
    if(arr1.length !== arr2.length){
        return false;
    }

    for(let i = 0; i < arr1.length; i++){
        if(arr1[i] !== arr2[i]){
            return false;
        }
    }
    return true;
}

function onPowerData(powerStr){
    //powerStr.match(//);
    let parts = powerStr.split(",");
    let total = parseFloat(parts[0]);
    let tarif1 = parseFloat(parts[1]);
    let tarif2 = parseFloat(parts[2]);

    let output = `${total}&nbsp;&nbsp;${new Date()}  <br>`;
    fs.appendFileSync('./htdocs/nord.html', output);
}

function main(){
    let req_resp_index = 0;
    let responseBuffer = [];
    const port = new SerialPort('COM3', {
      autoOpen: true,
      baudRate: 4800,
      dataBits: 7,
      parity: 'even',
      stopBits: 1
    });

    port.on('error', function(err) {
      console.log('Serial Port Error: ', err.message);
    });

    port.on('data', function (data) {
        console.log('Data:', data);
        for(let i = 0; i < data.length; i++){
            responseBuffer.push(data[i]);
        }
        
        if(req_resp_index === 6){
            //last response which we want to actually parse
            if(responseBuffer.length < 41){
                return;
            }
            let withoutHeader = responseBuffer.slice(6, -3);
            let powerStr = String.fromCharCode.apply(null, withoutHeader);
            console.log(`Power stats: ${powerStr}`);
            onPowerData(powerStr);
            process.exit(0);
        } else {
            if(responseBuffer.length < responses[req_resp_index].length){
                //need to read more
                return;
            }
            if(byteArrayEquals(responseBuffer, responses[req_resp_index])){
                console.log(`Response ${req_resp_index+1} matched.`);
                //clear
                responseBuffer = [];
                //send next request
                req_resp_index++;
                port.write(Buffer.from(requests[req_resp_index]));        
            } else {
                throw Error(`Response ${req_resp_index+1} contained unexpected data or bad length.`);
            }
        }               
    });

    //initial write which starts everything
    port.write(Buffer.from(requests[req_resp_index]));
}



main();

package.json

{
  "name": "powerstats",
  "version": "1.0.0",
  "description": "",
  "main": "main.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "serialport": "^7.1.5"
  }
}

sor.js

const SerialPort = require('serialport');
const fs = require('fs');


//request reset on address /?9999999
let request_init   = [ 0x2f, 0x3f, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x21, 0x0d, 0x0a ];
//select register "51"
let request_select_register_51 = [0x06, 0x30, 0x35, 0x31, 0x0d, 0x0a];
//.R1.0030().
let request_register_R1_30 = [
    0x01, 0x52, 0x31, 0x02, 0x30, 0x30, 0x33, 0x30, 0x28, 0x29, 0x03, 0x60
];

let request_register_R1_50 = [
    0x01, 0x52, 0x31, 0x02, 0x30, 0x30, 0x35, 0x30, 0x28, 0x29, 0x03, 0x66
];     	

let request_register_R1_100 = [
    0x01, 0x52, 0x31, 0x02, 0x30, 0x31, 0x30, 0x30, 0x28, 0x29, 0x03, 0x62
];     	
//select via serial number
let request_select = [ 0x2f, 0x3f, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x32, 0x21, 0x0d, 0x0a ];



//ack
let response1 = [0x2f, 0x41, 0x53, 0x0d, 0x0a];
//.P0.(18060583).a
let response2 = [0x01, 0x50, 0x30, 0x02, 0x28, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x32, 0x29, 0x03, 0x60];
//.0030(18060583).
let response3 = [0x02, 0x30, 0x30, 0x33, 0x30, 0x28, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x32, 0x29, 0x03, 0x01];
//.0100(0D010556).
let response4 = [0x02, 0x30, 0x31, 0x30, 0x30, 0x28, 0x30, 0x44, 0x30, 0x31, 0x30, 0x35, 0x35, 0x36, 0x29, 0x03, 0x70];
let response5 = [0x2f, 0x41, 0x53, 0x0d, 0x0a];
//.P0.(18060583).a
let response6 = [0x01, 0x50, 0x30, 0x02, 0x28, 0x31, 0x38, 0x30, 0x36, 0x30, 0x35, 0x38, 0x32, 0x29, 0x03, 0x60];
//.0050(+006511.71,+006511.71,+000000.00)..
//41 bytes
let response7 = [
    0x02, 0x30, 0x30, 0x35, 0x30, 0x28, 0x2b, 0x30, 0x30, 0x36, 0x35, 0x31, 0x31, 0x2e, 0x37, 0x31, 0x2c, 0x2b,
    0x30, 0x30, 0x36, 0x35, 0x31, 0x31, 0x2e, 0x37, 0x31, 0x2c, 0x2b, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x2e,
    0x30, 0x30, 0x29, 0x03,0x02
];

let requests = [
    request_init,
    request_select_register_51,
    request_register_R1_30,
    request_register_R1_100,
    request_select,
    request_select_register_51,
    request_register_R1_50
];

let responses = [
    response1,
    response2,
    response3,
    response4,
    response5,
    response6
];

function byteArrayEquals(arr1, arr2){
    if(arr1.length !== arr2.length){
        return false;
    }

    for(let i = 0; i < arr1.length; i++){
        if(arr1[i] !== arr2[i]){
            return false;
        }
    }
    return true;
}

function onPowerData(powerStr){
    //powerStr.match(//);
    let parts = powerStr.split(",");
    let total = parseFloat(parts[0]);
    let tarif1 = parseFloat(parts[1]);
    let tarif2 = parseFloat(parts[2]);

    let output = `${total}&#9;&#9;${new Date()}  <br>`;
    fs.appendFileSync('./htdocs/sor.html', output);
}

function main(){
    let req_resp_index = 0;
    let responseBuffer = [];
    const port = new SerialPort('COM5', {
      autoOpen: true,
      baudRate: 4800,
      dataBits: 7,
      parity: 'even',
      stopBits: 1
    });

    port.on('error', function(err) {
      console.log('Serial Port Error: ', err.message);
    });

    port.on('data', function (data) {
        console.log('Data:', data);
        for(let i = 0; i < data.length; i++){
            responseBuffer.push(data[i]);
        }
        
        if(req_resp_index === 6){
            //last response which we want to actually parse
            if(responseBuffer.length < 41){
                return;
            }
            let withoutHeader = responseBuffer.slice(6, -3);
            let powerStr = String.fromCharCode.apply(null, withoutHeader);
            console.log(`Power stats: ${powerStr}`);
            onPowerData(powerStr);
            process.exit(0);
        } else {
            if(responseBuffer.length < responses[req_resp_index].length){
                //need to read more
                return;
            }
            if(byteArrayEquals(responseBuffer, responses[req_resp_index])){
                console.log(`Response ${req_resp_index+1} matched.`);
                //clear
                responseBuffer = [];
                //send next request
                req_resp_index++;
                port.write(Buffer.from(requests[req_resp_index]));        
            } else {
                throw Error(`Response ${req_resp_index+1} contained unexpected data or bad length.`);
            }
        }               
    });

    //initial write which starts everything
    port.write(Buffer.from(requests[req_resp_index]));
}



main();