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Input signal Classification and Types of Sensors 97

Output signal

off delay off delay off delay
FIGURE 2.94 OFF delay.

2.9.7.8 ON/OFF Delay Logic
ON/OFF delay logic combines ON and OFF delay so that the output
will be generated only after the object has been detected for a prede-
termined period of time, and will drop out only after the object is no
longer detected for a predetermined period of time. Combining ON
and OFF delay smoothes the output of the inductive proximity con-
trol (Fig. 2.95).

2.9.7.9 One-Shot Delay
One-shot logic generates an output of predetermined length no mat-
ter how long an object is detected. A standard one-shot must time out
before it can be retriggered. One-shot logic is useful in applications
that require an output of specified length (Fig. 2.96).

Input signal

Output signal
on delay off delay
FIGURE 2.95 ON/OFF delay.

Input signal

Output signal
One shot One shot

FIGURE 2.96 One-shot.