Galil DMC-1700 Manual De Usuario

then it follows that G(s) must have magnitude of 

|G(j500)| = |A(j500)/L(j500)| = 160 

and a phase 

arg [G(j500)] = arg [A(j500)] - arg [L(j500)] = -135

° + 194°  = 59° 

In other words, we need to select a filter function G(s) of the form 

so that at the frequency 

ωc =500, the function would have a magnitude of 160 and a phase lead of 59 degrees. 

These requirements may be expressed as: 

|G(j500)| = |P + (j500D)| = 160 

and 

arg [G(j500)] = tan-1[500D/P] = 59

° 

The solution of these equations leads to:  

P = 160cos 59

° = 82.4  

500D = 160sin 59

° = 137 

Therefore, 

and 

The function G is equivalent to a digital filter of the form: 

D(z) = 4KP + 4KD(1-z-1) 

where 

∗

D = 4 

∗ KD ∗ T 

and 

∗ KD = D/T 

Assuming a sampling period of T=1ms, the parameters of the digital filter are:  

The DMC-1700/1800 can be programmed with the instruction: 

In a similar manner, other filters can be programmed.  The procedure is simplified by the following table, which 
summarizes the relationship between the various filters.