Siemens SIMATIC ET 200S Operating Instructions Manual page 281

The Interpulse Period of the Digital Input DI Is Too Short
The 2PULSE detects an interpulse period that is too short on the positive edge on the digital
input DI if:
Interpulse period + on-delay ≤ off-delay.
Response of the 2PULSE to an interpulse period that is too short:
• ERR_PULS is set.
• The current off-delay is deleted.
• The on-delay is not started.
• The signal level at the digital output DO remains at 1.
ERR_PULS is deleted with the next negative edge on the digital input DI.
Figure 5-13
Retriggering the Current On-Delay
The 2PULSE starts a new on-delay on the positive edge on the digital input DI if:
On-delay > pulse duration + interpulse period
This deletes the current off-delay.
The digital output DO is only set if signal level 1 is present on the digital input DI longer than
the on-delay. This enables you to filter rapid pulse trains.
Figure 5-14
Technological Functions
Operating Instructions, 02/2007, A5E00124867-05
The Interpulse Period Is Too Short
Retriggering the Current On-Delay
2PULSE
5.3 Modes and Functions
281