57 lines
1.7 KiB
JavaScript
57 lines
1.7 KiB
JavaScript
'use strict';
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const Stampit = require('stampit');
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const Put = require('put');
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module.exports = Stampit()
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.init(function () {
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const FC = 1;
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let init = () => this.addResponseHandler(FC, onResponse);
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let onResponse = (unitId, pdu, cb) => {
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let fc = pdu.readUInt8(0);
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if (fc !== FC) {
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cb(`ReadCoils: Invalid FC ${fc}`);
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} else {
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let byteCount = pdu.readUInt8(1);
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// let bitCount = byteCount * 8;
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let resp = {
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unitId,
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fc: fc,
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byteCount: byteCount,
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payload: pdu.slice(2),
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data: []
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};
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let counter = 0;
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for (let i = 0; i < byteCount; i+=1) {
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let h = 1, cur = pdu.readUInt8(2 + i);
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for (let j = 0; j < 8; j++) {
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resp.data[counter] = (cur & h) > 0 ;
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h = h << 1;
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counter += 1;
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}
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}
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cb && cb(null, resp);
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}
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};
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this.readCoils = (unitId, start, quantity) => {
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return new Promise((resolve, reject) => {
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let pdu = Put().word8(FC).word16be(start).word16be(quantity).buffer();
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this.queueRequest(unitId, FC, pdu, (err, resp) => {
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if (err) {
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reject(err);
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} else {
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resolve(resp);
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}
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});
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});
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};
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init();
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});
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