Eaton easyE4 Manual page 363

Figure 177: Response of the FT function block
Output value of the FT-PT1 signal smoothing filter function block, Tangent
Tangent
The output value is based on the following equation:
Y(t) = [T /T ] ∙ [ K ∙ ( X(t)-Y(t-1) ) ]
A G P
Y(t) = Calculated output value at time t
T =Scan time (calculated internally)
A
T = Recovery time
G
K = Proportional gain
P
X(t) = Actual value at time t
Y(t-1) = Calculated output value at time t-1
Scan time
Scan time T depends on the set recovery time value.
A
At recovery time T
G
T ≦ 1000 ms
G
T > 1000 ms
G
Cycle time to scan time
The ratio of cycle time cyc to sampling time T A should be such that the sampling time is
much larger than the cycle time (by a factor of approximately 10): T A =10 ∙ t cyc . The
sample time is set indirectly with the value for recovery time T G (please refer to the
table above).
The following therefore applies: t cyc << T A .
easyE4 10/19 MN050009 EN www.eaton.com
6.1 Manufacturer function blocks
Internal calculation of
the scan time T
A
T = 10 ms
A
T = T G /100
A
6. Function blocks
359