Application code has suddenly started running 50% slower

[Poley]

Hi all, I have obviously been adding logic as my model progresses and I have now suddenly had it make everything 50% slower.

For example, this 100ms trigger has always sent the CAN transmit block inside at 100ms. It is now sending at 150ms. This is happening to the whole model now, everything is 50% slower (Even tasks with sample rate of 1s are 50% slower)

Poley_1-1623753881773.png

100ms trigger block:

Poley_0-1623753847138.png

In other uC's I've used in Simulink before I have seen issues like this when program memory is nearly full, Is there anything the reports back how much program or data memory has been used after a build like Microchip's blockset does? 

I am hoping the memory isn't the issue because there is not much logic in at all yet and will be over double it's current state when finished.

Thanks in advance!

[mariuslucianand]

Hello @Poley ,

We shall investigate this with the profiler block. This block adds a header and footer code in the s-function  in which it is placed and takes the counter value of a timer (20Mhz). It returns the difference in ticks between entering and exiting moments of the function.

My guess is that at some point, the task which is triggered by the model fixed-step, used to drive all the systems, takes more than the time Simulink expects. For example, if the step size is set to 50us but it takes between 50us and 100us, then it will be triggered at every 100us. (backend, the fixed-step value, sets a timer, which triggers the step function. If the interrupt occurs while the core is executing the handler, then the interrupt will continue running the handler, will clear the interrupt bit when exiting the handler. The next handler execution will be triggered when the interrupt appears again). In this particular situation, the system becomes 50% slower and this is what I guess it happens with your model. 

So my suggestion is to start using the profiler block maybe there is some room for optimization.

Hope this helps,

Marius

[Poley]

Hi @mariuslucianand 

Can you please have a quick look at my simplified model that still produces the fault I am seeing (CAN runs at 150ms not 100ms)?

If I have one of either of these blocks commented out then it runs at the correct rate (100ms):

Poley_0-1623834956197.png

Is there a better way of doing what I am trying to do? The box on the left I need to receive 96 CAN messages every 100ms on CAN2 (They are staggered and not all at once) and then the right subsystem I need to transmit 16 CAN message on CAN2 every 100ms as well. In my main model I also have 8 messages being sent at 100ms on CAN0 and duplicated onto CAN1.

Will appreciate any feedback on this as it currently has me completely stuck with a short deadline, thank you!

[mariuslucianand]

Hello @Poley ,

I can't generate the code because of the following message: "The data dictionary 'VA_BMS.sldd' was not found." Can you please attach that as well?

@paulvlase , can you have a look on Poley's model?

Regards,

Marius

[Poley]

Hi @mariuslucianand 

Sorry, I thought I had included it! 

This one has the DD included.

Thanks!

[Poley]

Hi @mariuslucianand 

Does this model now run?

@paulvlase Am I using the CAN receive incorrectly? 

Thanks!

[Poley]

Hi @mariuslucianand @paulvlase 

Is is possible to check if there is an update to looking at this please?

This CAN receive/transmit scheduling is really affecting the progress of the project now, I am hoping it is just a case of me using the blocks wrong and therefore will have an easy solution.

Thank you!

[Poley]

Hi @mariuslucianand 

Thank you for the reply, how can I use the profiler block to diagnose what is causing this issue? Thanks!