Getting started on Linux

Running the IO-device application on Linux

Install dependencies

You need to have cmake version at least 3.13 installed. It is available in Ubuntu 19.04 and later.

To install on Ubuntu 16.04 or 18.04, follow the instructions here: https://blog.kitware.com/ubuntu-cmake-repository-now-available/

It is also possible to install it via snap:

sudo snap install cmake --classic

When using it, you might need to replace cmake with snap run cmake. If uninstalling the default cmake, the snap-installed version should be used by default after reboot.

Optional dependencies (for development and documentation of the p-net stack):

sudo apt install -y \
    clang-tools \
    doxygen \
    graphviz

Download and compile source

Clone the source:

mkdir profinet
cd profinet
git clone https://github.com/rtlabs-com/p-net.git

Compile:

cd p-net
mkdir build
cd build
cmake ..
make all
make install

or maybe

cmake .. -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=OFF -DBUILD_SHARED_LIBS=ON -DUSE_SCHED_FIFO=ON

Use the -j flag to make to enable parallel build.

Depending on how you installed cmake, you might need to run snap run cmake instead of cmake.

The make install step is to install scripts for manipulating IP settings, control LEDs etc.

Run the Linux demo application

If you need to set a static IP-address (adapt IP address and network adapter name):

sudo ifconfig eth0 192.168.137.4 netmask 255.255.255.0 up

Usage of the demo IO-device application:

$ ./pn_dev --help

Demo application for p-net Profinet device stack.

Wait for connection from IO-controller.
Then read buttons (input) and send to controller.
Listen for LED output (from controller) and set LED state.
It will also send a counter value (useful also without
buttons and LED).
Button1 value is sent in the periodic data. Button2 triggers an alarm.

The LED is controlled by writing '1' or '0' to the control file,
for example /sys/class/gpio/gpio17/value
A pressed button should be indicated by that the first character in
the control file is '1'.
Make sure to activate the appropriate GPIO files by exporting them.
If no hardware-controlling files in /sys are available, you can
still try the functionality by using plain text files.

Assumes the default gateway is found on .1 on same subnet as the IP address.

Optional arguments:
    --help       Show this help text and exit
    -h           Show this help text and exit
    -v           Incresase verbosity
    -i INTERF    Set Ethernet interface name. Defaults to eth0
    -s NAME      Set station name. Defaults to rt-labs-dev
    -l FILE      Path to control LED. Defaults to not control any LED.
    -b FILE      Path to read button1. Defaults to not read button1.
    -d FILE      Path to read button2. Defaults to not read button2.

Run the sample application:

cd build
make pn_dev
sudo ifconfig eth0 192.168.137.4 netmask 255.255.255.0 up
sudo ./pn_dev -v

On Raspberry Pi:

sudo build/pn_dev -v -l /sys/class/gpio/gpio17/value -b /sys/class/gpio/gpio22/value -d /sys/class/gpio/gpio27/value

Note that you must set up the GPIO files properly first (see the Raspberry Pi page).

Adjust log level

If you would like to change the log level, run ccmake . in the build directory. It will start a menu program. Move to the LOG_LEVEL entry, and press Enter to change to DEBUG. Press c to save and q to exit.

You need to re-build the project for the changes to take effect.

Run tests and generate documentation

Run tests (if you told cmake to configure it):

cd build
make check

Run a single test file:

cd build
./pf_test --gtest_filter=CmrpcTest.CmrpcConnectReleaseTest

Create Doxygen documentation:

cd build
make docs

The Doxygen documentation ends up in build/html/index.html

The clang static analyzer can also be used if installed. From a clean build directory, run:

scan-build cmake ..
scan-build make

Setting Linux ephemeral port range

This is the range of random source ports used when sending UDP messages. Profinet requires that the UDP source port should be >= 0xC000, which is 49152 in decimal numbers.

To change the ephemeral port range:

echo "49152 60999" > /proc/sys/net/ipv4/ip_local_port_range

This should typically be done at system start up.