@MikeyH Hi Mike,
We found out that there were changes to systemd in Bookworm. On the clean image, there is a problem in DNS after installing DWM. We will adjust the DWM installation accordingly so that everything works on Bookworm and older distributions. We'll let you know when we have a solution.
Cheers,
Jan
@AlexanderH Hi,
I'm sorry. For some reason I didn't get an email notifying me that you had replied. I'm glad you finally resolved the issue.
Cheers,
Jan
@AlexanderH Hi Alexander,
do you see any error messages in the system log? If so, what kind?
Does setting the outputs work as expected?
When reading inputs, I think you should both write and read within the same I2C() call — in other words, both counters should be non-zero. Usually, sending a request and receiving a response over I²C takes much less time than the REXYGEN task execution period. That’s why the I2C() function is designed to send data and, if a response is expected, receive it within the same cycle. I don’t know the exact details of the PCF8574A protocol, but I would assume that you need to perform the write and the read together in one call.
By the way, the code you pasted looks a bit broken here on the forum – that’s probably due to Markdown formatting. Please enclose the entire script in a code block using triple backticks (```) or upload it here as a text file. That way it will be much easier to read.
Cheers,
Jan
@har Hi har,
This error is related to the timing issue of the 'data_collect' task. The task takes longer to complete than the allotted time. Based on the image, I would guess that the Python block will take the most time to execute. In your case, I would inspect the timing of the whole project and also the diagnostics of task (Target ->Diagnostics -> data_collect and select the Task tab as shown bellow).
Cheers,
Jan
Hi har,
Check if RexCore is running. I see that you are solving the Python code in another thread. It is possible that your code is not only causing the error, but also causing the entire RexCore to crash. Try connecting to the Raspberry via SSH and enter the command:
systemctl status rexcore
Cheers,
Jan
@stepan-ozana
The problem is caused by a large value in the parameters tn and tp. The change occurs, but it is very slow. For a faster transition between values, set lower parameter values. For an immediate change, set 0.
@stepan-ozana Hello,
thank you for your report.
Please, what version of REXYGEN are you using? I've tested it now on 3.0.4.17197 and everything seems to work. I'm attaching a printscreen and the project.
myproject_exec.mdl myproject_task.mdl
Best regards,
Jan
Hello Štěpán,
Thanks for the detailed summary — that’s really helpful!
Regarding the first experiment with the SETPS command:
The reason the CNSTEST1:scv parameter wasn’t updated is due to the SETF parameter of the SETPS block being set to "on". In this configuration, the value is only updated on a rising edge at the SET input.
To allow the value to be updated continuously, set SETF to "off". This way, the parameter will be updated in each cycle regardless of input transitions.
As for the issue with setting the CNA:filename parameter:
The filename specified here is not part of the application on the target device. Instead, the file resides on the host PC, and its contents are imported into the project during compilation.
That’s why the filename parameter cannot be changed online — it only serves as a reference for the compiler, not as a runtime variable.
Similarly, updating the nmax parameter isn't possible either, because REXYGEN does not support dynamic arrays — both the size and content of arrays are fixed during compilation.
As a general rule, parameters that can be modified online via SETP blocks are the same ones you can manually change in Watch mode — in other words, those that are not greyed out in the parameter list. If a parameter is greyed out, it means it’s read-only during runtime and cannot be changed programmatically either.
Cheers,
Jan
@stepan-ozana
Thanks, that looks great! I'll modify the schema a little more to match the conventions of the other blocks and include it in the installation.
@stepan-ozana Thank you for your valuable insights! Your contribution to the collection of examples is greatly appreciated.
In the original 'EKF.zip' file mentioned at the beginning of this thread, the timing parameters were incorrectly set—my apologies for that. The best way to correct them is by changing the start and stop values in the task1 block to -1, as outlined in the manual. The log message 'CoreWarning GTimer: Period overtime.' appears whenever the task execution exceeds the maximum allowed time, which can be observed in Diagnostics. If this warning appears in the log while the Max time in Diagnostics does not exceed the allocated execution time (20 ms in the case of EKF.zip), it indicates an error.
We would greatly appreciate any further insights and improvements from your side. I had planned to simulate measurement noise similarly to your approach—by adding white noise to the measurement vector—but I hadn’t considered process noise. For your reference, I’m sharing the updated version of the example, which includes your reference model and the corrected timing parameters.
@stepan-ozana
First of all, thank you very much for adding the reference model. If you agree, I would like to add this model to the example on EKF, which is already part of the daily version of REXYGEN.
As for the timing. I think the problem may be in the Python block, which takes significantly longer to execute than the native blocks. Try looking in the Diagnostics and at the statistics on the execution of the task.
