Siemens SIDOOR AT40 System Manual page 63

Reversing (Retraction attempt)
When an obstruction is detected, the obstruction reversing system can be used to initiate an
immediate full or partial reverse - a retraction attempt. This system is simply termed
"reverse". The system remains active as long as the initial drive order is not actively
changed. You can find an example of this in Section Overcome obstruction (Page 62).
Parameter assignment
The number of reversals (retraction attempts) can be defined in parameters p3864 and
p3881. If the number is set to "0", the obstruction reversing system is disabled in the
corresponding direction.
A variable wait time can be configured (p3865 and p3882) after each retraction attempt (on
reaching the corresponding reverse target position). The drive remains stopped during the
wait time.
The reversing distance or the type of reverse (full or partial reverse) can be configured to an
accuracy of ±2 cm in parameters p3866 and p3883.
If the system is obstructed while reversing, all still open reversing actions are immediately
ended, and wait mode is activated (see Wait mode (Page 64)). A following drive order can
also be configured in parameters p3867 and p3884, which is activated at the same time as
the switch to wait mode.
After the configured number of reversing operations/retraction attempts have been made,
wait mode is activated (see Wait mode (Page 64)). A following drive order can also be
configured, which is activated at the same time as the switch to wait mode (p3868 and
p3885).
While the obstruction reversing system is active, any change in an external drive order (see
Table 6-74 DCMD signal (Page 206)) immediately ends all open reversing actions (including
the cancelation of wait mode).
Note
A reverse due to a drive order being changed is part of the basic software, and is not
affected by the reversing on account of an obstruction described here (Open → Close, Close
→ Open).
Combination of retry and reverse
The reverse and retry systems can be combined. The combination is subject to the following
rules:
● A reverse is made after executing the configured number of retries. The action is
repeated for the number of configured reverses.
● Parameters p3863 and p3880 have no effect when reversing is activated.
● Wait mode becomes active after the last reverse.
● If the number of retries and reversing operations is set to "0", the "retry" following drive
order has a higher priority than the "reverse" drive order.
AT40, ATD400V, ATD400K, ATD4xxW, ATD400S, ATE250S, ATD400T
System Manual, 06/2016, A2B00096162-AN
Controllers
6.2 Drive functions
63