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CODESYS Benchmark

The CODESYS benchmark is an example application that allows deterministic control and test of the CODESYS SoftPLC. The application is defined such that a main task occurs every 250us. Within the main task is a configurable workload which iterates a number of user defined times. The specific workload is configurable to either: “floating point”, “arithmetic”, or “boolean” operations. Cycle execution times are measured from which minimum, maximum, and jitter measurements are derived. These measurements allow performance characterization of the CODESYS SoftPLC on the target system.

../../../_images/031.jpg

This benchmark can be ran natively, or in a container environment. Running in a container environment is easier to setup, but will perform slightly worse than running natively. If you’re running this benchmark for the first time, it is recommended to run in a container environment.

See also

Microservice: CODESYS Linux Runtime and CODESYS Edge Gateway

The following steps are applicable to:

../../../_images/target_generic4.png

  1. Install a container engine, if not already done:

    logo_debian logo_ubuntu

    The preferred container engine on Debian and Canonical® Ubuntu® based systems is Docker. Install Docker on the target system, if not already done.

  2. On the target system, install the codesys-benchmark-scripts package from the ECI repository. Setup the ECI repository, then perform the following command to install this component:

    logo_debian logo_ubuntu

    $ sudo apt install codesys-benchmark-scripts

  3. Navigate to /opt/benchmarking/codesys and build the codesyscontrol container image with the codesys-eci-benchmark benchmark:

    logo_debian logo_ubuntu

    $ cd /opt/benchmarking/codesys/docker
$ docker build -f ./Dockerfile.controlruntime \
     -t codesyscontrol:4.5.0.0 . \
     --build-arg ECI_DEB=codesys-eci-benchmark \
     --build-arg CDS_VERSION=4.5.0.0

    Note

    If you are building behind a proxy, you may need to add the following build arguments: --build-arg http_proxy="http://<proxy:port>" --build-arg https_proxy="http://<proxy:port>".

  4. Navigate to /opt/benchmarking/codesys/utility. This directory contains a number of useful scripts for improving the real-time performance of the CODESYS Linux runtime.

    The scripts available at /opt/benchmarking/codesys/utility include:

    • start_codesys_native.sh : Optimizes the system (see list below), stops non-essential services, and restarts the CODESYS Linux runtime

    • start_codesys_container.sh : Optimizes the system (see list below) and starts the containerized CODESYS Linux runtime with RT priority.

    • taskset_codesys.sh : Optimizes the system (see list below)

    The scripts also perform the following runtime optimizations:

    • Uses CAT to allocate exclusive access of half the last-level cache to cores 1 & 3 (13th generation processors and older) or 2 & 4 (14th generation processors and newer)

    • Assigns benchmark thread affinity to isolated cores

    • Assigns non-benchmark thread affinity to core 0

    • Changes the priority of benchmark thread to 90 (using: chrt -f 90)

    • Disables kernel machine check interrupt

    • Increases the thread runtime utilization to infinity

    When executing the scripts, not all task affinity can be changed. This is expected behavior. An example output is shown below:

    $ sudo /opt/benchmarking/codesys/utility/start_codesys_native.sh
Stopping unecessary services
Failed to stop ofono.service: Unit ofono.service not loaded.
Failed to stop wpa_supplicant.service: Unit wpa_supplicant.service not loaded.
Failed to stop bluetooth.service: Unit bluetooth.service not loaded.
Stopping Docker Daemon
Warning: Stopping docker.service, but it can still be activated by:
  docker.socket
Stopping Codesys Runtime
Disabling Machine Check
Disabling RT runtime limit
New COS default: 0xff0
Changing CPU affinity of existing interrupts
setting 1 to affine for core 0
setting 4 to affine for core 0
setting 8 to affine for core 0
setting 9 to affine for core 0
setting 12 to affine for core 0
setting 14 to affine for core 0
setting 16 to affine for core 0
setting 18 to affine for core 0
setting 27 to affine for core 0
setting 29 to affine for core 0
setting 120 to affine for core 0
setting 121 to affine for core 0
setting 123 to affine for core 0
setting 124 to affine for core 0
setting 125 to affine for core 0
setting 126 to affine for core 0
taskset: failed to set pid 3's affinity: Invalid argument
taskset: failed to set pid 4's affinity: Invalid argument
taskset: failed to set pid 16's affinity: Invalid argument
taskset: failed to set pid 23's affinity: Invalid argument
Starting Codesys Runtime
Changing affinity of Codesys Runtime tasks
Codesys preparation complete.

  5. Run the start_codesys_container.sh script available at /opt/benchmarking/codesys/utility to reload the CODESYS Linux runtime and start the benchmark:

    logo_debian logo_ubuntu

    $ cd /opt/benchmarking/codesys/utility
$ sudo ./start_codesys_container.sh

  6. The CODESYS benchmark is configured to host a web visualization at http://<target-ip-address>:8080. Open this URL in a web browser. If the benchmark is working correctly, the web visualization should be similar to the following image:

    Tip

    If you cannot connect to the web server, verify that port 8080 is not blocked by a firewall. On Red Hat® Enterprise Linux® based systems, you may need to open port 8080 in the firewall with the following commands:

    $ sudo firewall-cmd --zone=public --add-port=8080/tcp --permanent
$ sudo firewall-cmd --reload
    ../../../_images/031.jpg

  7. Run the taskset_codesys.sh script at /opt/benchmarking/codesys/utility to move all CODESYS tasks to isolated CPU cores (1,3 or 2,4) and change the priority of all CODESYS tasks to RT:

    $ sudo ./taskset_codesys.sh

    Use the RESET buttons in the web visualization to reset the statistics after running the taskset_codesys.sh script. This CODESYS benchmark demonstrates that real-time performance can be achieved with proper kernel and runtime configurations.

  8. Use the slider and arrow buttons to increase or decrease the number of workload iterations per cycle.

  9. The colored LEDs are connected to variables mapped to an OPC UA server. Connect an OPC UA client to the CODESYS OPC UA server to read/write the values. You can download a popular free OPC UA client called UaExpert from: https://www.unified-automation.com/products/development-tools/uaexpert.html.