isobus-parser-js

JavaScript utility that parses Isoblue raw data

Getting Started

Installation

The library can be installed with npm using

$ npm install isobus-parser

parse(data, smallbyte,bigbyte,mul,add)

Taking data array and extracts a message from data array according to input parameters: smallbyte, bigbyte, mul and add Function makes no assumption about endianness of data. Considers the first element of data to be less significant than the second Function will fail if caller tries to retrieve too many bytes (js uses only 53 bits in numbers)

Parameters

data {Arrray} of 8 bytes

[smallbyte][] {Number} specify the region of bytes to parse; represents the lowest byte to use

bigbyte {Number} specify the region of bytes to parse; respresents the end byte

respresents the range for the consecutive bytes that comprise the message

i.e.: smallbyte=0, bigbyte=2 would parse the first 3 bytes in the data word

• mult {Number} Represent factor to multipy the parsed byte sequence

add {Function} Represent factor to add to the parsed byte sequence

Usage Example

var data = [0x01, 0x01, 0x01, 0x01, 0x0, 0x0, 0xFF, 0xFF];
function test_parse () {
  parse(data, 1, 3, 3, 2);

Output: 
 197381.0

parseArray(input, config)

Parses raw input array from IsoBlue

Parameters

input {Array} of objects comprised of PGNS, a 8 byte data array, and a time stamp. Requires a JSON configuration file Ine the following format: input=[ {pgn:XXXXX, data: [0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0] timestamp=XX }, {pgn:XXXXX, data:[0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0] timstamp=XX }, ... ... ]

[config][] {File} Required file that contains extraction information for a given message in the following format: config = { 'parameter': { pgn: ##, low: ##, high: ##, mul: ##, add: ## } ... ... }

Usage Example

  config = {
  'enginespeed': {
    signed: false,
    pgn: 61444,
    low: 3, 
    high: 4,
    mul: 0.125,
    add: 0
  }
};

input=[
{pgn:61444,
 data: [0xFF, 0xFF, 0xFF, 0x95, 0x47, 0xFF, 0xFF, 0xFF],
 timestamp:.94
},
{pgn:61444,
 data: [0xFF, 0xFF, 0xFF, 0x01, 0x1C, 0xFF, 0xFF, 0xFF],
 timestamp:.94
},
{pgn:61444,
 data: [0xFF, 0xFF, 0xFF, 0x0E, 0x1C, 0xFF, 0xFF, 0xFF],
 timestamp:.94
},
{pgn:61444,
 data: [0xFF, 0xFF, 0xFF, 0xF8, 0x1B, 0xFF, 0xFF, 0xFF],
 timestamp:.94
}
];
parseArray(input,config);

Output:
{enginespeed=[{timestamp=0.94, measurement=2290.625}, {timestamp=0.94, measurement=896.125}, {timestamp=0.94, measurement=897.75}, {timestamp=0.94, measurement=895.0}]}

getBytes(payload)

Parses a 16 character hex string into an array of 8 bytes, assuming the first charcter in the string is the least significant byte.

Parameters

payload {String} 16 character hex string (padded with 0 bytes if necessary)

Usage Example

payload= 'FFFFFFFFFFFFFF22';
getBytes(payload);

Output:
[255.0, 255.0, 255.0, 255.0, 255.0, 255.0, 255.0, 34.0]

getPgn(canString)

converts Isobus formatted string hex value from speadsheet into decimal PGN number

Parameters

canString {String} Isobus formatted string hex value

Usage Example

canString= '0ff46x';
getPgn(canString);

Output:
65350.0

h2d(h)

Converts hex string into decimal number

Parameters

h {String} hex string to be converted to decimal

Usage Example

hval= "FFFF";
h2d(hval);

Output:
 65535.0