How can I tell EmbeddedCo​der/Simuli​nkCoder to not evaluate expressions containing Matlab tunable parameters when generating C-code from Simulink?

Hi, I have a saturation block in Simulink where I set upper and lower limits based on a tunable parameter and have the output port generated as global variable:

In the generated C-code the lower limit expression is evaluated to:

srt_gyroXsaturated = rtU.gyro_X >= srt_gyroLimitX ? srt_gyroLimitX :
  rtU.gyro_X <= -0.349040151F ? -0.349040151F : rtU.gyro_X;

What I want is that '-srt_gyroLimitX' is not evaluated to '-0.349....' but left "as is" in the generated code. How can I achive that?

Answer 1

[Saurabh Gupta]

For tunability in code generation, the parameter needs to be a variable. Parameters specified as expressions are evaluated and inlined. You could specify the limits as 2 separate variables to ensure that code generation preserves the tunability.

[Matphree]

Yeah, that what I did, but I prefer to have one +/-limit, is that possible?

Answer 2

[Ben Rancici]

Same question as Matphree: how to prevent block parameter evaluation in the generated code?

I don't understad Saurabh Gupta's solution.