about error in stateflow

dear,

when i implement stateflow in block to mult or add signals in stateflow, i have this error:

_Cannot solve algebraic loop involving 'SUMOFPRODUCT/Sumofproduct/Product1' because it consists of blocks that cannot be assigned algebraic variables, i.e., blocks with discrete-valued outputs, blocks with non-double or complex outputs, Stateflow blocks, or nonvirtual subsystems

Need for helping!

Best regards!

Pham van Dung

[Walter Roberson]

Please read the guide to tags and retag this question; see http://www.mathworks.co.uk/matlabcentral/answers/43073-a-guide-to-tags

Answer 1

[Azzi Abdelmalek]

You have an algebraic loop means that in your model you have a feedback through a block which don't contain any delay, it's like you write y(n)=2*y(n)+1, which is not correct, you should write y(n+1)=2*y(n)+1. to correct insert before your feedback a unit delay block

[Pham Van Dung]

i didn't use any function in my project, just only use add and product block in simulinks. This is my model:

http://www.mediafire.com/?v46tbexxc0z572s

Can you give me the ideal for this problem. thanks you so much!!

Pham Van Dung

[Azzi Abdelmalek]

you have two feedback to your chart, add two unit delay block from simulink/discrete