When pulsed signals are applied to a Digital Input the input state may
change so fast that it cannot be seen or detected by an application. The
solution is to capture the pulse and hold the signal state long enough
to be detected and then processed. An input can be configured to latch on
either the 1 (ON) state or the 0 (OFF) state. A pulse as short a 1 milli-
second can be detected.
Once latched a timer can be configured to reset the latch after a period
suitable for the application. Alternatively the latch might hold the
condition indefinitely until it is manually reset or acknowledged by the
application programming. This may be appropriate in a fire alarm situation.
Pulses may also be stretched using Debounce.
HELP Topics: IO/Inputs/[DIN]/Latching