State Writer: How can I reset state for delay block with frame-based processing?

In a Reset Function block I would like to use a State Writer to reset the state of a Delay block. However, this Delay block uses frame based input processing, i.e. the Input processing is selected to be "Columns as channels (frame based)". The State Writer block refuses to reset the delay's state with a diagnostic error:

Block 'MySystem/Delay' has attributes or configurations that are not supported by State Writer block 'MySystem/Reset Function/State Writer1'.
Caused by:
Block 'MySystem/Delay' has frame-based signal at input port 1. 
Block 'MySystem/Delay' has frame-based signal at output port 1. 

So is there a better State Writer block somewhere that can actually reset the state of my Delay block? After all, state data is just data - why can't the State Writer reset it?

My desire is to create an entrypoint in generated code (i.e. a reset function) that will clear the delay block's internal state to 0.

Answer 1

[Aabha]

Hi @Keith Lundberg,

I faced a similar issue while trying to use a ‘State Writer’ block to reset the state of a ‘Delay’ block. This issue is due to the ‘State Writer’ block not supporting ‘Frame Based’ processing in Simulink. But, as a workaround, you can try any of the following steps and check if it fixes the issue:

1. Instead of using a ‘State Writer’ block, you can manually reset the ‘Delay’ block by enabling the option for the ‘External Reset’ in the block parameters and implementing control logic for the same. To understand more about how the ‘External Reset’ can be enabled, please refer to the following documentation link: https://in.mathworks.com/help/releases/r2022b/simulink/slref/delay.html#d125e46693
2. Additionally, the ‘Frame-Based’ data can be converted to ‘Sample-Based‘ data and vice versa using ‘Buffer’ blocks. This will help to convert the data into whatever format is necessary for the respective block. To understand more about ‘Frame-Based’ and ‘Sample-Based’ data processing, please refer to the following link: https://in.mathworks.com/help/releases/r2022b/dsp/ug/sample-and-frame-based-concepts.html Please refer to the following documentation link to understand more about the ‘Buffer’ block: https://in.mathworks.com/help/releases/r2022b/dsp/ref/buffer.html
3. To generate code with an entry-point function for reset, implement a custom C-function and integrate it by modifying the generated C-code, or use a ‘MATLAB Function Block’ to handle the reset logic programmatically. To understand more about the ‘MATLAB Function Block’, please refer to the following documentation link: https://in.mathworks.com/help/releases/r2022b/simulink/ug/what-is-a-matlab-function-block.html

I hope this answers your question.