mobject-client

mobject-client is a JavaScript client designed for easy interaction with the mobject-server. It facilitates communication with automation software, specifically designed to work seamlessly with Beckhoff's TwinCAT HMI and NodeJs environments. This package includes two main clients: AdsRpcClient for general-purpose use and TcHmiRpcClient for integration with TwinCAT HMI projects.

ADS already supports most use cases. This server and client combination was created to provide a true server and client implementation which can be expanded upon. Currently the client and server supports synchronous and asynchronous requests. The amount of data sent in a call is only limited by the ADS router memory. Requests and responses are automatically chunked.

Installation

npm install mobject-client

Usage

Getting Started

In your JavaScript project, require the mobject-client to start interacting with your server.

const { AdsRpcClient } = require("mobject-client");

Using AdsRpcClient

The AdsRpcClient is the primary client for most users. Here's how to instantiate and use it:

const client = new AdsRpcClient("127.0.0.1.1.1", 851, "Main.server");

// Connect to the server
await client.connect();

// Make a remote procedure call
const parameters = {
  /* key-value pairs of the parameters */
};
const methodReturnValue = await client.rpcCall("MethodName", parameters);

Constructor Parameters

• amsNetId: The AMS Net ID of the target machine, defaults to "127.0.0.1.1.1".
• adsPort: The ADS port, defaults to 851. symbolName: The symbol name for the API endpoint, defaults to "MAIN.server".
• methodName: The method name to call, defaults to "HandleRequest".
• config: Additional configuration options.

Parameters Object

The parameters object for rpcCall consists of key-value pairs corresponding to the method's parameters. These can be any JavaScript primitive, array or object, which will be automatically serialized for the call.

Building for TcHmi (Prior to NuGet package release)

For projects using TwinCAT HMI, where modules cannot be directly used, a bundled distribution file is generated through Webpack:

npm run build-tchmi-javascript-file

In time this will be replaced with an official NuGet package for TwinCAT HMI, but until then you will manually build.

Using in TwinCAT HMI

You will need to map the HandleRequest method in the server configuration of TwinCAT HMI. Once done, you can create a client and send rpc calls using client.rpcCall().

const client = new TcHmiRpcClient("%s%PLC1.MAIN.server.HandleRequest%/s%");

// Make a remote procedure call
const parameters = {
  /* key-value pairs of the parameters */
};
const methodReturnValue = await client.rpcCall("MethodName", parameters);

This creates TcHmiRpcClient.bundle.js in the dist folder, which can be included in your TcHmi project.