Problem with linking my Signal to my own sub VI

[pengxin]

Hi 

The first picture is my main VI and the Blue icon is the sub VI that i made , however there is an error as shown in the 3rd picture when i run it.

In the subVI (2nd picture), i am using a polynomial 1st order to  fit my original signal and perform more calculation. If I have used those functions and paste it in the main VI and it was working when i run the main VI.

I took out those functions and made it into a sub VI and it gave error when i run the main VI. I could not figure out the problem.

Could anyone help me on this. Thank you 

[srikrishnaNF]

Hi pengxin,

  First of all you are using your subvi in a wrong way.See your subvi is expecting an integer value where as you are giving a dynamic data type.So what you can do is to convert the dynamic data type to proper data type using convert from dynamic data type express vi and try.

Thanks and regards,

srikrishnaNF

[Dennis_Knutson]

It's your input to the subVI. You've got a scalar and of course you can't do a curve fit on a single point. You can see the red dot on the input to the subVI. That means that the dynamic data type is being coerced to something else. You can use a waveform data type as an input. Or, right click on the Signals input and select Create>Graph Indicator then right click on that and select Change to Control. Personally, I hate the dynamic data type and would use the simpler waveform data type.

[pengxin]

Hi 

Let me try it now . If you have time u can paste me an VI to see the solution you mention 

[Dennis_Knutson · Accepted solution]

Here's a VI. Use one or the other.

[pengxin]

Thank you Krishna and Dennis !!!