PROFINET Node-RED Interface

This project realizes an interface between Node-RED and PROFINET. It consists of an interface between PROFINET and Node.js and an interface for Node-RED. Using this interface, response times below 50 ms can be achieved.

The project is published in source code only and must therefore be compiled before it can be used. After the compiling and installation process, PROFINET IO devices can easily be used in Node-RED.

Installation of the RT-Image and PN Driver

Before the addon can be used on an IOT2040, the realtime image must be set up. It can be obtained on the same page as the PN Driver (SIOS). The image must be flashed and the IOT needs to be set up.

The next step is to copy the driver kernel object/module on the IOT. The file PNDevDrv_32.ko must be copied from PN_Driver_IOT2000_V2.4.0\PN_Driver_IOT2000\ko\ to the folder /usr/src/ on the IOT. A symlink to this file must be created from the modules folder. Also the modprobe-files need to be updated using depmod. On the RT-Image V2.4 this can be done with the following command:

ln –s /usr/src/PnDevDrv_32.ko /lib/modules/4.4.154-cip28-rt20
depmod -a

As this module should be loaded on every startup, an udev-rules file must be copied to the IOT. The file pndev.rules can be found in PN_Driver_IOT2000_V2.4.0\PN_Driver_IOT2000\ko\ and must be copied to /etc/udev/rules.d/.

After a reboot, the network interface X2 P1 (/dev/eth1) can only be used by the PN Driver, so no ssh connection is possible anymore using this interface.

Prerequirements for Compiling

GNU Make

Make sure you have GNU Make installed. This can be tested with the command make in a terminal. GNU Make for Windows can be obtained on multiple sources. MSYS2 is an project, which ports Linux tools to Windows. Follow the steps on the msys2 Homepage for installing and updating the base environment. Make can then be installed in the MSYS2 console with the following commands:

pacman -S mingw-w64-x86_64-make
ln -s /mingw64/bin/mingw32-make.exe /mingw64/bin/make.exe

The last step is adding the directory containing make to the PATH-variable. The path should be <Install-DIR>\msys64\mingw64\bin\. This variable can be changed in the system settings or using the following PowerShell commands as admin:

$path = [Environment]::GetEnvironmentVariable('PATH','Machine')
$newpath = $path + ';<Install-DIR>\msys64\mingw64\bin\'
[Environment]::SetEnvironmentVariable("PATH",$newpath,'Machine')

If the installation was successful, running make in a normal console (cmd) should now work.

Downloading IOT2040 SDK

The SDK can be downloaded in SIOS. Only the SDK is needed, the Eclipse plugin is optional. The extracted folder containing sysroots will be called SDKROOT.

Downloading the PN Driver

The driver (and headers, shared objects, ...) can be downloaded in SIOS. For the compiling of this project only the driver zip is needed.

Two folders need to be prepared:

1. PROFINET_H

   This folder should contain every header file of the zip (found in
   ...\PN_Driver_IOT2000\pn-test-app_eclipse_project\src\source\pnd\src\common and
   ...\PN_Driver_IOT2000\pn-test-app_eclipse_project\src\source\pnd\inc)

2. PROFINET_A

This folder should contain the static library libpndriver.a of the zip file. This file can be found in ...\PN_Driver_IOT2000\test_app_bin. The file PnDev_DriverU32.so is not needed for compilation, but will later be needed to run the program.

Download NAN (Native Abstractions for Node.js)

As the name suggests, this library is needed for creating an addon to Node.js. It can be downloaded on GitHub or installed using npm. The folder containing the headers will be needed for compilation and will be called NAN_H.

Compiling the addon

Setup environment vars for compiling

This project can be compiled in a console or an IDE like eclipse. In both the environment vars need to be set.

In the cmd, vars can be set using SET <varname>=<value>. Linux users can set these using

<varname>=<value>
export <varname>

 or if you want to immediately start a program like make:

env <var1>=<val1> <var2>=<val2> ... <program name e. g. make>

Environment vars can also be set in the eclipse preferences (Window > Preferences > C/C++ > Build > Environment).

The following vars need to be set:

Compiling

The last step is to extract the contents of the file ProfinetNodeAddon.zip and run make inside the extracted folder. This should compile the program without errors. At the end of the compilation process, the file build\default\addon.node should exist.

Building and installing the npm module

The contents of the npm-package.zip must be extracted to a folder on the IOT. Also copy the file addon.node and PnDev_DriverU32.so in this directory. The folder should now contain the following files:

• profinetNode/
  • icons/
    • pn.png
    • pn.svg
  • addon.node
  • package.json
  • PnDev_DriverU32.so
    
  • profinetNode.html
  • profinetNode.js

If the folder ~/.node-red/ does not already exist, create it using:

mkdir ~/.node-red

Change the directory and install the package using:

cd ~/.node-red
npm install ../profinetNode # Change foldername to the path of the module

Add and modify autostart of Node-RED

In the iot200setup tool the autostart can be activated in Software > Manage Autostart Options > Auto Start node-red. This creates the file /etc/init.d/launch_node-red.sh. The content of this file must be changed in order to enable the use of the addon. This can be done using nano:

nano /etc/init.d/launch_node-red.sh

Change the content to:

Usage

Creating a TIA Project

The PN Driver needs a configuration file, which can easily be created in TIA. Create a new project and add the "device" "PROFINET Driver V2.1". In this device, add the Interface submodule "IOT20x0" (V2.1).

After this step, other devices can be added and the configuration can be changed like any normal PLC project.

The configuration can then be exported using the compile button.

Adding nodes in Node-RED

Open the Node-RED UI in a browser (http://<IP-Address>:1880). The new category profinet should be in the palette. In order to use inputs and outputs, the interface must first be configured.

Add an "PN connection configuration" node to the flow and edit its configuration. The file upload button must be used to upload the configuration created within TIA. This xml-file can be found in the subdirectory AdditionalFiles\PNDriver\ of the TIA project folder.

In order to connect (equals RUN-Mode), true must be sent to the "PN connection configuration" node. To disconnect (equals STOP-Mode), false must be sent.

In- and outputs can be used with the configured addresses. The datatype Boolean uses a Boolean and datatypes up to DWord use Number. As a LWord exceeds the storage of a Number, a string of digits is used instead.