Integral Term

[Edris]

Hello 

The integral term (Ki) is unitless in labVIEW, and it is calculated based on Kc/Ti . As Kc is unitless on its own, what factor should be multiplied by (Kc/Ti ) to make it unitless? Is it the sampling time? 

Thanks

[Bob_Schor]

Wow.  Do you want to put this in a little context?  What functions are you trying to program/use?  What toolkits?  Have you looked at the Help for the functions you want to use?

Bob Schor

[nathand]

I assume here you're referring to the PID toolkit. Internally the toolkit multiplies the integral gain by the sampling time dt, or by the amount of time since the last call if no dt is provided.

As an aside, I like to think of Kc not as unitless, but rather as a ratio of output to input - an error of some amount of input units results in a change of so many output units.