Short description
The on-/off- delay function block can set an output after a configured on-delay time and then reset it again upon expiration of a second configured time.
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Connection |
Description |
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Input Trg |
You trigger the on-delay with a positive edge (0 to 1 transition) at input Trg (Trigger). You trigger the off-delay with a negative edge (1 to 0 transition). |
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Parameter |
T
H
is the on-delay time for the output (output signal transition 0 to 1). Retentivity on = the status is retentive in memory |
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Output Q |
Q switches on upon expiration of a configured time T H if Trg is still set. It switches off again upon expiration of the time T L and if Trg has not been set again. |
Parameters TH and TL
The actual value of another already-programmed function can provide the on-delay time and off-delay time set in parameter TH and TL:
Analog comparator: Ax - Ay
Analog threshold trigger: Ax
Analog amplifier: Ax
Analog multiplexer: AQ
Analog ramp: AQ
Mathematic instruction: AQ
PI controller: AQ
Up/Down counter: Cnt
For the 0BA7 and later version devices, you can additionally use the actual values of the following already-programmed functions:
On-delay: Ta
Off-delay: Ta
On-/off-delay: Ta
Retentive on-delay: Ta
Wiping relay(pulse output): Ta
Edge triggered wiping relay: Ta
Asynchronous pulse generator: Ta
Stairway light switch: Ta
Multiple function switch: Ta
Stopwatch: AQ
Analog filter: AQ
Average value: AQ
Max/Min: AQ
Threshold trigger: Fre
You select the required function by the block number.
For information on the validity and accuracy of the time base, refer to the LOGO! Manual.
Timing diagram
Description of the function
A 0 to 1 transition at input Trg triggers the time TH.
If the status at input Trg is 1 for at least the duration of the configured time TH, LOGO! sets the output to logical 1 upon expiration of this time (output is on-delayed to the input signal).
The time TH resets if the status at input Trg resets to 0 before this time has expired.
The 1 to 0 transition at the output triggers the time TL is triggered.
If the status at input Trg remains 0 at least for the duration of a configured time TL, the output resets to 0 upon expiration of this time (output is off delayed to the input signal).
The time TL resets if the status at input Trg returns to 1 before this time has expired.