node-red-contrib-knx-ultimate/KNXEngine/dptlib/dpt16.js

Control your KNX intallation via Node-Red! Single Node KNX IN/OUT with optional ETS group address importer. Easy to use and highly configurable.

/**
* KNXEngine - a KNX protocol stack in Javascript
* (C) 2020-2022 Supergiovane
*/

const knxLog = require('./../KnxLog');

//
// DPT16: ASCII string (max 14 chars)
//

// Write to BUS
exports.formatAPDU = function (value) {
  if (typeof value != 'string') {
    knxLog.get().error("Must supply a string value. Autoconversion to string");
    try {
      value = value.toString();
    } catch (error) {
      value = "DPT Err";
    }

  }

  var buf = Buffer.alloc(14);
  if (this.subtypeid === "001") buf.write(value, 'latin1');
  if (this.subtypeid === "000") buf.write(value, 'ascii');
  return buf;

}

// Read from BUS
exports.fromBuffer = function (buf) {
  if (buf.length != 14) {
    knxLog.get().error("DPT6: Buffer should be 14 byte long, got", buf.length);
    return null;
  }
  if (this.subtypeid === "001") return buf.toString('latin1');
  if (this.subtypeid === "000") return buf.toString('ascii');
  

}

// DPT16 basetype info
exports.basetype = {
  bitlength: 14 * 8,
  valuetype: 'basic',
  desc: "14-character string",
  "help":
    `// Send a text to a display
msg.payload = "Hello!"
return msg;`,
  "helplink": ""
}

// DPT9 subtypes
exports.subtypes = {
  // 16.000 ASCII string
  "000": {
    use: "G",
    "desc": "DPT_String_ASCII", "name": "ASCII string",
    "force_encoding": "US-ASCII"
  },

  // 16.001 ISO-8859-1 string
  "001": {
    use: "G",
    "desc": "DPT_String_8859_1", "name": "ISO-8859-1 string",
    "force_encoding": "ISO-8859-1"
  },
}