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.

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.

Native EnvironmentContainer Environment

1. Setup the ECI repository, if not done already.

2. Install the CODESYS ECI Benchmark PLC logic and convenience scripts from the ECI repository:

   ECI Deb PackagesECI RPM Packages

   

   $ sudo apt install codesys-eci-benchmark codesys-benchmark-scripts
   

3. Use the provided scripts to start the CODESYS Linux runtime. The scripts will perform various optimizations to minimize interrupts to the CODESYS Linux runtime. When the CODESYS Linux runtime starts, it will auto-load and execute the OPC UA Client Benchmark prebuilt PLC logic.

   $ sudo /opt/benchmarking/codesys/utility/start_codesys_native.sh
   

   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 provided scripts also perform the following runtime optimizations:

   • Uses Cache Allocation Technology (CAT) to allocate exclusive access of half the last-level cache to isolated cores (typically 1 & 3)

   • Assigns CODESYS task affinity to isolated cores (typically 1 & 3)

   • Assigns non-CODESYS task affinity to core 0

   • Disables kernel machine check interrupt

   • Increases 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.
   

4. Verify that CODESYS Linux runtime started correctly:

   $ sudo systemctl status codesyscontrol
   

   The output should show Active: active (running):

   $ sudo systemctl status codesyscontrol
   ● codesyscontrol.service - LSB: Prepares and starts codesyscontrol
        Loaded: loaded (/etc/init.d/codesyscontrol; generated)
        Active: active (running) since Fri 2023-03-03 19:59:10 MST; 1s ago
          Docs: man:systemd-sysv-generator(8)
       Process: 121981 ExecStart=/etc/init.d/codesyscontrol start (code=exited, status=0/SUCCESS)
         Tasks: 2 (limit: 14185)
        Memory: 13.0M
        CGroup: /system.slice/codesyscontrol.service
                └─121986 /opt/codesys/bin/codesyscontrol.bin /etc/CODESYSControl.cfg
   
   Mar 03 19:59:09 eci-test systemd[1]: Starting LSB: Prepares and starts codesyscontrol...
   Mar 03 19:59:10 eci-test codesyscontrol[121981]: codesyscontrol started
   Mar 03 19:59:10 eci-test systemd[1]: Started LSB: Prepares and starts codesyscontrol.
   

5. 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
   

   

6. 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:

   $ ./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.

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

8. 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.