Chapter 9—C445 Logic Engine and Expansion I/O
174
Power Xpert C445 Global Motor Management Relay
MN042003EN—January 2019
www.eaton.com
FILT—Single-Pole Low Pass Filter
The FILT function block is a single-pole low pass filter that filters the input signal. The time
constant is defined by FTIME.
The filter is implemented per the equation below.
For the proper operation of the filter, FTIME has to be greater than or equal to the program
scan time.
The filter can be pre-initialized using the SET and DATA inputs. When SET is true, the
output of the filter is pre-initialized with the value specified by the DATA input.
Example
In the following example, the FILT block is used to filter the Phase A current with the time
constant at 1 second and the program scan time set at 10 ms. The filtered current is made
available through a process data out. The filter is cleared when the motor is stopped.
Parameter
Data type
Description
SET
BOOL
Pre-initialize filter command
DATA
INT
Pre-initialize filter data
FTIME
INT
Filter time constant in milliseconds
IN
INT
Signal to be filtered
OUT
INT
Filtered output
