Filter Time Of A Digital Input - ABB REF 54 Series Technical Reference Manual, General

REF 54_
5.1.7.1.
44
Feeder Terminal
Technical Reference Manual, General
Table 5.1.7-1 Digital inputs available for the REF 54_ (Continued)
REF 541
Digital inputs / 15
total
1) These digital inputs can be programmed as either digital inputs or pulse counters, refer to Section
"Pulse counters" on page 45.

Filter time of a digital input

The filter time eliminates debounces and short disturbances on a digital input. The
filter time is set for each digital input of the REF 54_ feeder terminal. The operation
of input filtering is illustrated below.
t
0
Input
Filtered Input
Filter Time
Fig. 5.1.7.1.-1 Filtering of a digital input
In the figure above, the input signal is named 'Input', the filter timer 'Filter Time'
and the filtered input signal 'Filtered Input'. At the beginning, the input signal is at
high state, the short low state is filtered and no input state change is detected. The
low state starting from the time t
change in the input state is detected and the time tag attached to the input change is
t . The high state starting from t
0
Each digital input has a filter time parameter "Input # filter", where # is the number
of the digital input of the module in question (for example Input 1 filter).
Parameter Values
Input # filter
1....15000 ms
1)
In the feeder terminal revisions of Release 2.5 or later. Before Release 2.5: 1...65535 ms.
REF 543
25
t
1
Filter Time
exceeds the filter time, which means that the
0
is detected and the time tag t
1
Default
1) 5 ms
1MRS750527-MUM
REF 545
BIO2_7_BI7
BIO2_7_BI8
1)
BIO2_7_BI9
1)
BIO2_7_BI10
34
dipo_b
is attached.
1