Skip to content

Latest commit

 

History

History
129 lines (82 loc) · 3.75 KB

README.md

File metadata and controls

129 lines (82 loc) · 3.75 KB
Raw

Linux GPIB

The brand new General Purpose Interface Bus (GPIB, IEC-625-Bus), introduced by Hewlet-Packard in the late 1960s, can be accessed via linux-gpib. This module offers native bindings to the very fundamental read and write methods (ibrd() and ibwrt()). So if you want to access your lab bench devices using JavaScript, this module will be your solution.

Example

const GPIB = require( 'linux-gpib' );

// Connect to GPIB interface available at /dev/gpib0
const gpib = GPIB( 0 );

// And finally connect to your GPIB device with primary address 20
let specAnalyser = gpib.connect( { pad: 20 } );

// In this example its a Rohde & Schwarz FSP specturm analyser. We want to fetch
// the points recorded on TRACE1. So we transmit the command accordingly the
// user's manual.
specAnalyser.query( 'trac1? trace1' ).then( ( response ) => {

	// The data is transmitted as a string separated by commas. Convert them
	// into floats.
	let data = [];
	response.split(',').forEach( ( v ) => data.push( parseFloat( v ) ) );
	return data;

} ).then( ( data ) => {

	// Output data
	console.log( data );

	// Disconenct from device
	return specAnalyser.disconnect();

} ).catch( ( err ) => {

	// Something went wrong!
	console.error( err.message );

} );

API

The native bindings can be accessed as follows. The API documentation refers to GPIB.

const GPIB = require( 'linux-gpib' );

GPIB

const gpib = GPIB( minor );

Connects to a GPIB adapter available at /dev/gpib[minor] and returns an instance of GPIB.

Class: GPIB

Method: connect

const dev = gpib.connect( device );

Connects to the device described in device and returns an instance of Device.

device has the following properties:

  • pad: Primary GPIB address of the device.
  • sad: (optional) Secondary GPIB address.
  • timeout: (optional) Timeout for I/O operations. Possible values: "TNONE", "T10us", "T30us", "T100us", "T300us", "T1ms", "T3ms", "T10ms", "T30ms", "T100ms", "T300ms", "T1s", "T3s", "T10s", "T30s", "T100s", "T300s", "T1000s". Default: "T300ms".
  • send_eoi: (optional) Assert EOI line with last transmitted byte. Default: true.
  • eos: (optional) end-of-string mode. Default: 0x0.

Method: disconnectAll

gpib.disconnectAll().then( ... );

Disconnects from all connected devices. Returns a promise.

Class: Device

Method: write

dev.write( data ).then( ... );

Sends data to the connected device. Returns a promise. If data is a string, it is just transmitted. If data is an array, each item is transmitted successively, starting with the first item.

Method: read

dev.read().then( ... );

Reads data from the connected device. Returns a promise that will be resolved with the received data.

Method: query

dev.query( data ).then( ... );

Fristly writes data to and then reads data from the connected device. Returns a promise that will be resolved with the received data.

Method: disconnect

dev.disconnect( goToLocalMode ).then( ... );

Disconencts from device. Returns a promise. If goToLocalMode is true (default), it will bring the device back to local mode before disconnecting.

Requirements

Beside a GPIB-capbale measurement instrument you need a GPIB interface that is compatibile with linux-gpib. Furthermore linux-gpib must be installed and the GPIB-device must be fully configured. (Some of them need a firmware downloaded onto the device before beeing used. Google is your friend!)

Node.js must be available in version 4 or later.

Acknowledgement

Special thanks to:

  • 68ec020 for establishing Node.js 12 compatibility.