Triggered Strobe; Figure 1-15 Triggered Strobe - Siemens SIMATIC TI505 User Manual

Triggered Strobe

High Speed Counter Encoder Module User Manual
The triggered strobe mode generates an output that is On for one clock
period following the trigger, after the preset number of clocks has been
down counted to zero.
The output turns On when the preset number of clocks has been counted to
zero, or (preset value +1) clocks after the trigger pulse.
To repeat a cycle, a trigger is required. A trigger can be an external input or
the PLC can set the Reset Counter flag, WY19.03, .04, .07, or .08 for the
corresponding counter 2, 3, 5, or 6. After the trigger, the next valid clock
loads the preset into the counter. The last clock decrements the count to
zero and turns the output On. The next clock turns the output Off. If a
trigger does not occur, the count value continues to decrement, and the
output remains Off even through a rollover to the preset value.
A typical waveform for the Triggered Strobe mode of counting is presented
in Figure 1-15. The waveforms show that the output is initially Off after the
trigger and clock. The edge of the trigger starts the counter counting down
from the preset value. When the counter reaches 0, the output goes On for
one clock period then goes Off.
The output remains Off until the edge of the next trigger. In this example,
the preset value is 2.
Starts On
Pulse Input
Starts Off
Trigger, Reset, or
Programming
Output
Figure 1-15 Triggered Strobe Mode
20 20 2 1 0 –1 –2
20 19 2 1 0 –1 –2
–3 2 1 0 –1 –2
–3 2 1 0 –1 –2
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