Rate Limiter Block Error

I have a step source feeding into a rate limit block that feeds into a scope. All values are default, including the simulation parameters. When I run it there is a an error on the rate limit block that says: "Input signals to Rate Limiter 'untitled/Rate Limiter' are neither discrete nor continuous sample time signals. Only discrete or continuous input signals are supported"

However if I change the simulation default to fixed-step, then it works. I don't want to do this because I'll be adding other stuff that with probably run faster and more accurately with variable step size.

Can anyone tell me if there is something I can change to make the rate-limit block work with variable step size?

Answer 1

[Ryan G]

Try changing the sample time of the step to either -1 or a sample rate. The problem is the default rate is 0, which is neither continuous nor discrete.

[Kaustubha Govind]

It looks like the Step block in your model gets a Fixed-in-minor-step sample-time, which the Rate Limiter block cannot handle. Set the Step block's sample time to discrete as Ryan suggested, or use a Signal Specification block between the Step and Rate Limiter blocks and set its sample time to 0 if you'd like it to be treated as a continuous signal.