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# Control systems with different frequencies.

## Control systems with different frequencies.

(OP)
Hello,

I'm new in the forum and also kind of new in the Control systems world.
I'm trying to write the transfer functions of a control system:
------------>G1(z)------------>G2(z)----------->

In the z domain (discrete control). The problem is that G2 works at a different sampling rate than G1. That is, there is two blocks that resample the data.

------------>G1(z)------R1(z)------>G2(z)-----R2(z)------>

G1 works at 10Hz and G2 at 2Hz.
So R1 converts the data from 10 to 2 Hz by means of a zero order hold (MATLAB). And R2 converts from 2Hz to 10Hz with a delay (MATLAB).
How can I write the right transfer function of the system considering this?

Thank you very much!
Replies continue below

### RE: Control systems with different frequencies.

I'm unclear why you would convert back to 10Hz after you basically destroyed 80% of your data.

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Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
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### RE: Control systems with different frequencies.

(OP)
IRstuff, the reason is that G2(z) needs to operate at that frequency, and then the output of G2 is input for G1 that operates at 10Hz.

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