TeltonikaParser

Install this parser using npm: npm i complete-teltonika-parser

``javascript
const { ProtocolParser, parseIMEI, Data, GPRS } = require('complete-teltonika-parser')
const packet = '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'
let parsed = new ProtocolParser(packet)
console.log(parsed)
if (parsed.CodecType == "data sending") {
let data = parsed.Content as Data
} else {
let gprs = parsed.Content as GPRS
}

const imei = parseIMEI('000F333532303933303839313638383231')
console.log(imei)

`

Q: How can I know that a packet is the device imei or the data packet?

A: The packet containing the imei has a constant length: 34

`javascript
function processPacket (packet) {
if (packet.length == 34) {
return {
imei: parseIMEI(packet)
}
} else {
return {
dataPacket: new ProtocolParser(packet)
}
}
}
`

ProtocolParser has the following signature:

`typescript
class ProtocolParser {
Packet : string
Preamble: number
Data_Length: number
CodecID: number
Quantity1: number
CodecType: 'data sending' | 'GPRS messages'
Content : GPRS | Data | null
Quantity2: number
CRC: number
constructor(packet: string, basic_read: boolean, on_ioElement_error: (e: Error) => void) {
// code
}
}

class Data {
AVL_Datas : AVL_Data[]
}

class AVL_Data {
Timestamp : Date
Priority : number
GPSelement : GPSelement
IOelement : IOelement
}

class GPSelement {
Longitude : number,
Latitude : number,
Altitude : number,
Angle : number,
Satellites : number,
Speed : number
}

class IOelement {
EventID: number
ElementCount: number
Elements: {
[avlid: number]: number | string
}
}

class GPRS {
type : 5 | 6
isResponse : boolean
responseStr : string
}
`

Where if basic_read == true, then the property 'Content' will not be parsed.

Notice that values from IOelement.Elements can also be string. Thats because some values may be too bit to fit javascript's number type. To ilustrate that, here is the actual code to extract the value:
`typescript
function extractValue (x: string) => {
var y: number | string = parseInt(x, 16);
if (y > Number.MAX_SAFE_INTEGER) {
y = BigInt(0x${x}).toString();
}
return y;
}
``

NOTICE

- If the data packet has an invalid CRC, then the parser will fail throwing an exception;
- The only GPRS codec supported is Codec 12;
- This is a PROTOCOL parser. It does not parse the device IMEI. For that, use the function parseIMEI;
- The file "AVL Data Parser/IOelement" has some useful funcitons and an avl id translator for teltonika device model FMB640.