Siemens SIDOOR AT40 System Manual page 62

Controllers
6.2 Drive functions
Obstruction detection process
The obstruction detection is based on two processes that are independent of the direction:
force obstruction detection and stop obstruction detection.
The following definitions are based on the speeds and are thus independent of the direction.
The obstruction detection systems assume that the system is actively being moved (drive
order).
● Force obstruction detection
The current speed is > 90 mm/s, and drops by more than 90 mm/s in comparison to the
maximum speed reached during the current movement.
If the system then moves for the set duration (p3854 and/or p3871) at the upper force
limitation, a force obstruction is detected in the current drive direction.
● Stop obstruction detection
If the current speed is less than 10 mm/s for the set duration (p3853 and/or p3870), a
stop obstruction is detected in the current drive direction.
Overcome obstruction
The overcome obstruction system can be used to overcome a blocking obstruction by
repeated pushing. The system remains active as long as the initial drive order is not actively
changed.
Example
1. The drive order "close" is present.
2. The system closes.
3. An obstruction is detected before the end stop "closed" is reached.
4. The second of four retries is made.
5. The drive order "close" is overwritten by any other drive order.
6. The retry system is immediately exited.
7. The system responds according to the new drive order.
Parameter assignment
The number of retries to overcome the obstruction can be set in parameter p3860 or p3877.
If the number is set to "0", the overcome obstruction system is disabled in the corresponding
direction.
A variable waiting time can be configured before each retry (p3861 or p3878).
The type of drive control during this wait time can be "stop" or "deenergize" (p3862 or
p3879).
After the configured number of retries have been made, wait mode is activated (see the
following Section "Wait mode"). A following drive order can also be configured, which is
activated at the same time as the switch to wait mode (p3863 or p3880).
While the retry system is active, any external change to a drive order (see Table 6-74 DCMD
signal (Page 206)) immediately ends all open retry actions (including the cancelation of wait
mode).
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AT40, ATD400V, ATD400K, ATD4xxW, ATD400S, ATE250S, ATD400T
System Manual, 06/2016, A2B00096162-AN