keyence-hostlink

keyence-hostlink is a library that allows communication to KEYENCE PLC by Host link protocol

this is not a official library

to install

npm i -S keyence-hostlink

example usage

const { Hostlink } = require('./dist/index');

const link = new Hostlink({ timeout: 1000, host: '192.168.3.100', port: 8501 });

link.connect(() => {
  link.readItem('DM0', (error, data) => {
    console.log(error, data);
    process.exit();
  });
});

then the console will show

false {
  message: <Buffer 52 44 20 44 4d 30 0d 0a>,
  address: 'DM0',
  result: '00011\r\n',
  resultBuffer: <Buffer 30 30 30 31 31 0d 0a>
}

API

constructor(options)

create a hostlink instance, const link = new Hostlink(options)

• options:Net.NetConnectOpts use Nodejs Net options document is here

connect(callback)

connect to PLC

• callback:function when connect success, it will trigger callback

readItem(address, callback)

read a address and trigger callback when it done or timeout

• address:string for example 'DM0'
• callback:(error:boolean, responseData)=>void when read item fail, error will be true.

callback responseData will be follow structure

{
  message: Buffer, // request message send to server
  address: string, // address to get
  result: string | null, // server response result string
  resultBuffer: Buffer | null, // server response buffer
  error?: any, // error detail information
}

writeItem(address, value, callback)

write value into address, and callbake will trigger when write done.

• address: string for example 'DM0'
• value:string for example '100',
• callback (err?: Error | undefined) => void

if callback first parameter is undefined, it means success.