Node Ethernet/IP

A simple and lightweight node based API for interfacing with Rockwell Control/CompactLogix PLCs.

Prerequisites

latest version of NodeJS

Getting Started

Install with npm

npm install ethernet-ip --save

The API

How the heck does this thing work anyway? Great question!

The Basics

Getting Connected

const { Controller } = require("ethernet-ip");

const PLC = new Controller();
// Controller.connect(IP_ADDR[, SLOT])
// NOTE: SLOT = 0 (default) - 0 if CompactLogix
PLC.connect("192.168.1.1", 0).then(() => {
    console.log(PLC.properties);
});

Controller.properties Object

javascript
 {
    name: String, // eg "1756-L83E/B"
    serial_number: Number, 
    slot: Number,
    time: Date, // last read controller WallClock datetime
    path: Buffer,
    version: String, // eg "30.11"
    status: Number,
    faulted: Boolean,  // will be true if any of the below are true
    minorRecoverableFault: Boolean,
    minorUnrecoverableFault: Boolean,
    majorRecoverableFault: Boolean,
    majorUnrecoverableFault: Boolean,
    io_faulted: Boolean
}

Set the Clock of the Controller

NOTE

Controller.prototype.readWallClock

Controller.prototype.writeWallClock

Sync Controller WallClock to PC Datetime

const { Controller } = require("ethernet-ip");

const PLC = new Controller();
PLC.connect("192.168.1.1", 0).then(async () => {
    // Accepts a JS Date Type
    // Controller.writeWallClock([Date])
    await PLC.writeWallClock(); // Defaults to 'new Date()'
});

Set Controller WallClock to a Specific Date

const { Controller } = require("ethernet-ip");

const PLC = new Controller();
PLC.connect("192.168.1.1", 0).then(async () => {
    const partyLikeIts1999 = new Date('December 17, 1999 03:24:00');
    await PLC.writeWallClock(partyLikeIts1999); // Pass a custom Datetime
});

Reading Tags

NOTE: Currently, the

Tag

Reading Tags

Individually

const PLC = new Controller();

// Create Tag Instances const fooTag = new Tag("contTag"); // Controller Scope Tag const barTag = new Tag("progTag", "prog"); // Program Scope Tag in PLC Program "prog"

PLC.connect("192.168.1.1", 0).then(async () => { await PLC.readTag(fooTag); await PLC.readTag(barTag);

console.log(fooTag.value);
console.log(barTag.value);

}); ```

Additional Tag Name Examples ...

javascript
const fooTag = new Tag("Program:prog.progTag"); // Alternative Syntax for Program Scope Tag in PLC Program "prog"
const barTag = new Tag("arrayTag[0]"); // Array Element
const bazTag = new Tag("arrayTag[0,1,2]"); // Multi Dim Array Element
const quxTag = new Tag("integerTag.0"); // SINT, INT, or DINT Bit
const quuxTag = new Tag("udtTag.Member1"); // UDT Tag Atomic Member
const quuzTag = new Tag("boolArray[0]", null, BIT_STRING); // bool array tag MUST have the data type "BIT_STRING" passed in

Reading Tags as a

Group

const PLC = new Controller(); const group = new TagGroup();

// Add some tags to group group.add(new Tag("contTag")); // Controller Scope Tag group.add(new Tag("progTag", "prog")); // Program Scope Tag in PLC Program "prog"

PLC.connect("192.168.1.1", 0).then(async () => { await PLC.readTagGroup(group);

// log the values to the console
group.forEach(tag => {
    console.log(tag.value);
});

}); ```

Writing Tags

NOTE: You MUST read the tags first or manually provide a valid CIP datatype. The following examples are taking the latter approach.

Writing Tags

Individually

const PLC = new Controller();

// Create Tag Instances const fooTag = new Tag("contTag", null, DINT); // Controller Scope Tag const barTag = new Tag("progTag", "prog", BOOL); // Program Scope Tag in PLC Program "prog"

PLC.connect("192.168.1.1", 0).then(async () => {

// First way to write a new value
fooTag.value = 75;
await PLC.writeTag(fooTag);

// Second way to write a new value
await PLC.writeTag(barTag, true);
console.log(fooTag.value);
console.log(barTag.value);

}); ```

Writing Tags as a

Group

const PLC = new Controller(); const group = new TagGroup();

// Create Tag Instances const fooTag = new Tag("contTag", null, DINT); // Controller Scope Tag const barTag = new Tag("progTag", "prog", BOOL); // Program Scope Tag in PLC Program "prog"

group.add(fooTag); // Controller Scope Tag group.add(barTag); // Program Scope Tag in PLC Program "prog"

PLC.connect("192.168.1.1", 0).then(async () => { // Set new values fooTag.value = 75; barTag.value = true;

// Will only write tags whose Tag.controller_tag !== Tag.value
await PLC.writeTagGroup(group);

group.forEach(tag => {
    console.log(tag.value);
});

}); ```

Lets Get Fancy

Subscribing to Controller Tags

const { Controller, Tag } = require("ethernet-ip");

const PLC = new Controller();
// Add some tags to group
PLC.subscribe(new Tag("contTag")); // Controller Scope Tag
PLC.subscribe(new Tag("progTag", "prog")); // Program Scope Tag in PLC Program "prog"
PLC.connect("192.168.1.1", 0).then(() => {
    // Set Scan Rate of Subscription Group to 50 ms (defaults to 200 ms)
    PLC.scan_rate = 50;
// Begin Scanning
PLC.scan();
});
// Catch the Tag "Changed" and "Initialized" Events
PLC.forEach(tag => {
    // Called on the First Successful Read from the Controller
    tag.on("Initialized", tag => {
        console.log("Initialized", tag.value);
    });
// Called if Tag.controller_value changes
tag.on("Changed", (tag, oldValue) => {
    console.log("Changed:", tag.value);
});
});

Demos

• Monitor Tags for Changes Demo

const { Controller, Tag } = require("ethernet-ip");

// Intantiate Controller
const PLC = new Controller();
// Subscribe to Tags
PLC.subscribe(new Tag("TEST_TAG"););
PLC.subscribe(new Tag("TEST", "Prog"););
PLC.subscribe(new Tag("TEST_REAL", "Prog"););
PLC.subscribe(new Tag("TEST_BOOL", "Prog"););
// Connect to PLC at IP, SLOT
PLC.connect("10.1.60.205", 5).then(() => {
    const { name } = PLC.properties;
// Log Connected to Console
console.log(`\n\nConnected to PLC ${name}...\n`);

// Begin Scanning Subscription Group
PLC.scan();
});
// Initialize Event Handlers
PLC.forEach(tag => {
    tag.on("Changed", (tag, lastValue) => {
        console.log(${tag.name} changed from ${lastValue} -> ${tag.value});
    });
})

Built With

• NodeJS - The Engine
• javascript - ES2017 - The Language

Contributers

• Canaan Seaton - Owner - GitHub Profile - Personal Website
• Patrick McDonagh - Collaborator - GitHub Profile
• Jeremy Henson - Collaborator - Github Profile

Related Projects

• Node Red

Wanna become a contributor? Here's how!

License

This project is licensed under the MIT License - see the LICENCE file for details