@frangoteam/fuxa
Version:
Web-based Process Visualization (SCADA/HMI/Dashboard) software
88 lines (78 loc) • 1.83 kB
JavaScript
const snap7 = require('node-snap7').S7Client();
/**
* S7Client Datatype
*
* @typedef {object} S7ClientDatatype
* @property {number} bytes - Number of bytes
* @property {function} parser - Convert Buffer to {bool|number|string}
* @property {function} formatter - Convert {bool|number|string} to Buffer
* @property {number} S7WordLen - S7WL type
*/
function _gen(bytes, bFn, S7WordLen) {
return {
bytes,
parser: (buffer, offset = 0) => buffer['read'+bFn](offset),
formatter: v => {
const b = new Buffer(bytes);
b['write'+bFn](v);
return b;
},
S7WordLen
}
}
/**
* @enum
*/
const Datatypes = {
/**
* BOOL
* @type {S7ClientDatatype}
*/
BOOL: {
bytes: 1,
parser: (buffer, offset = 0, bit = 0) => +buffer.readUInt8(offset) >> bit & 1 === 1,
formatter: v => new Buffer([v ? 0x01 : 0x00]),
S7WordLen: snap7.S7WLBit
},
/**
* BYTE
* @type {S7ClientDatatype}
*/
BYTE: _gen(1, 'UInt8', snap7.S7WLByte),
/**
* WORD
* @type {S7ClientDatatype}
*/
WORD: _gen(2, 'UInt16BE', snap7.S7WLWord),
/**
* DWORD
* @type {S7ClientDatatype}
*/
DWORD: _gen(4, 'UInt32BE', snap7.S7WLDWord),
/**
* CHAR
* @type {S7ClientDatatype}
*/
CHAR: {
bytes: 1,
parser: (buffer, offset = 0) => buffer.toString('ascii', offset, offset + 1),
formatter: v => new Buffer(v, 'ascii'),
S7WordLen: snap7.S7WLByte
},
/**
* INT
* @type {S7ClientDatatype}
*/
INT: _gen(2, 'Int16BE', snap7.S7WLWord),
/**
* DINT
* @type {S7ClientDatatype}
*/
DINT: _gen(4, 'Int32BE', snap7.S7WLDWord),
/**
* REAL
* @type {S7ClientDatatype}
*/
REAL: _gen(4, 'FloatBE', snap7.S7WLReal),
};
module.exports = Datatypes;