Forced Checking Procedure - Siemens Sinamics S110 Function Manual

Safety Integrated Functions
8.4 Basic Functions
8.4.5

Forced checking procedure

Forced dormant error detection or test for the switch-off signal paths
The forced dormant error detection function at the switch-off signal paths is used to detect
software/hardware faults at both monitoring channels in time and is automated by means of
activation/deactivation of the "Safe Torque Off" function.
To fulfill the requirements of EN 954-1 / ISO 13849-1 regarding timely error detection, the
two switch-off signal paths must be tested at least once within a defined time to ensure that
they are functioning properly. This functionality must be implemented by means of forced
dormant error detection function, triggered either in manual mode or by the automated
process.
A timer ensures that forced dormant error detection is carried out as quickly as possible.
● p9659 SI timer for the forced dormant error detection.
Forced dormant error detection must be carried out at least once during the time set in this
parameter.
Once this time has elapsed, an alarm is output and remains present until forced dormant
error detection is carried out.
The timer returns to the set value each time the STO function is deactivated.
When the appropriate safety devices are implemented (e.g. protective doors), it can be
assumed that running machinery will not pose any risk to personnel. For this reason, only an
alarm is output to inform the user that a forced dormant error detection run is due and to
request that this be carried out at the next available opportunity. This alarm does not affect
machine operation.
The user must set the time interval for carrying out forced dormant error detection to
between 0.00 and 9000.00 hours depending on the application (factory setting: 8.00 hours).
Examples of when to carry out forced dormant error detection:
● When the drives are at a standstill after the system has been switched on.
● When the protective door is opened.
● At defined intervals (e.g. every 8 hours).
● In automatic mode (time and event dependent)
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NOTICE
The timer of the Basic Functions will be reset if the associated forced dormant error
detection is executed and the Extended Functions are used simultaneously. The
corresponding alarm of the Basic Functions is not triggered.
Discrepancy is not checked at the terminals used to select the Basic Functions as long
as STO is set by the Extended Functions. That is, the forced checking procedure of the
Basic Functions always has to be executed without simultaneous selection of STO or
SS1 by the Extended Functions. It is otherwise not possible to verify the correct control
through the terminals.
Function Manual, 10/2008, 6SL3097-4AB10-0BP0
Drive functions