The ability to use an external input to specify a dynamic value for the built-in Integrator block's "Upper Saturation Limit" parameter is not available in Simulink.
To work around this issue, you can use core Simulink blocks to build your own integrator block that allows you to specify dynamic values for its parameters. See the attached Simulink model, named continuous_integrator.mdl, for an example that demonstrates a custom integrator block with external inputs for its "Upper Saturation Limit" and "Lower Saturation Limit" parameters.
