Why does the Rate Limiter block require the "absolute time support" option to be checked during code generation even though I am using a discrete model?

I have a Rate Limiter block in the Simulink model. The model is configured to be built for the ERT target. However, when I try to build the model, I receive the following error:

Error building Real-Time Workshop target for block diagram 'ratelimiter'. MATLAB error message:

Error using ==> rtwgen

Block 'ratelimiter/Rate Limiter' uses absolute time, which is not supported with the current configuration. Consider selecting the support 'absolute time' ERT option.

Answer 1

[MathWorks Support Team]

The Rate Limiter block uses the value of absolute time (that is, the time from the beginning of the program to the present time) to calculate it's outputs and hence depends on the absolute time as mentioned in the documentation at the following URL:

 <http://www.mathworks.com/help/releases/R2011a/toolbox/simulink/slref/ratelimiter.html>

As an alternative, use the Dynamic Rate Limiter block which performs the same functionality and yet does not require the value of the absolute time unlike the Rate Limiter block.

[Sandip Kumar]

Hi James,

Sorry for the delay in responding. I would like to thank you for this feedback. We will investigate this.