You can first query the parameter with "getparam" to get clarity on the data type:
>> tg.getparam(gcb,'Gain')
ans =
int8
-1
In this case, you need to pass an explicit int8 Type:
>> tg.setparam('MyModel/Gain','Gain',int8(-2));
If the parameter type is fixed-point, you will see the following output for "getparam":
>> val = tg.getparam(gcb,'Gain')
val =
-1
DataTypeMode: Fixed-point: binary point scaling
Signedness: Signed
WordLength: 32
FractionLength: 31
In this case, it is easiest to re-use the same "fi" object returned by "getparam":
>> val.Value = -2;
>> tg.setparam('MyModel/Gain','Gain',val);
To avoid fixed-point types for the Gain parameter, enable the model setting: Gain parameters inherit a built-in integer type that is lossless
For an interactive approach, you can also check the parameter data types in the SLRT Explorer "Parameters" tab and "Type" column:
The new Parameter Quantization Advisor app (R2022b+) may also be useful:https://www.mathworks.com/help/simulink/slref/parameterquantizationadvisor-app.html
More information on controlling block parameter data types in Simulink can be found in the documentation:
