syntax error on simulink

I am getting an error in simulink in a Fcn block:

m*(u(1) - l*u(3)*u(3)*sin(u(2)) + l*u(4)*cos(u(2)))

Can someone help urgently. Thanks in advance.

[Walter Roberson]

Could you confirm that m and I are scalar workspace variables at that point?

https://www.mathworks.com/help/simulink/ref_obsolete_blocks/fcn.html

[Jonas]

Can you urgently post the error message you are getting?

[Moopela Tlhone]

The expression: m*(u(1) - l*u(3)*u(3)*sin(u(2)) + l*u(4)*cos(u(2)))

in 'Model'

has a syntax error

Answer 1

[Walter Roberson]

Simulink Fcn blocks give syntax errors if you name variables in them that are not variables that exist in the workspace.

I suspect that either m or I or both are not currently defined.

You might tend to think that Fcn blocks would wait until execution time to look for variables existing, but if I recall correctly, they parse the string at block initialization time