ABB i-bus® EIB Universal Interfaces US/U 4.2 US/U ... - WindowMaster

ABB i-bus ® EIB
5 Special functions
5.1 Debounce time and
minimum operation time
Universal Interfaces
US/U 2.2, GH Q631 0074 R0111
US/U 4.2, GH Q631 0070 R0111
The following section outlines special functions which could not be described
in connection with the parameters and objects due to lack of space.
A debounce time or a minimum operation time can be defined for each input.
Debounce time
If a pulse edge is detected at the input, the input reacts to it immediately
(e.g. with the sending of a telegram). The debounce time T D starts at the
same time. During the debounce time, the signal is not evaluated at the input.
The following example clarifies this:
Input signal
Detected pulse edge
T D T D T D
When a pulse edge is detected at the input, further pulse edges are ignored
for the duration of the debounce time T D .
Minimum operation time
This function differs from the debounce time in that the telegram is only sent
once the minimum operation time has elapsed. The function operates as
follows:
If a pulse edge is detected at the input, the minimum operation time starts.
No telegrams are sent on the bus at this point. The signal at the input is
observed during the minimum operation time. If a further pulse edge occurs
at the input during this period, it is interpreted as a new operation and the
minimum operation time is restarted. If the input signal does not change
during the minimum operation time, a pulse edge is detected and a telegram
is likewise sent on the bus.
The following example clarifies this:
Input signal
T M
T M
Detected pulse edge
Since only two pulse edges remain stable for the duration of the minimum
operation time T M , only these edges are recognised as valid.
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