Forced Checking Procedure - Siemens SINUMERIK 840D sl Function Manual

Safety Functions integrated in the drive
5.1 General information about SINAMICS Safety Integrated
Parameter overview
● p9761 SI password input
● p9762 SI new password
● p9763 SI password acknowledgment
5.1.5

Forced checking procedure

Forced checking procedure and test of the switch-off signal paths
The forced checking procedure of the switch-off signal paths is used to detect software/
hardware faults at both monitoring channels in time and is automated by selecting/deselecting
the "Safe Torque Off" function.
To fulfill the requirements of ISO 13849-1:2006 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 checking
procedure, triggered either in manual mode or automated in the process.
A timer ensures that the forced checking procedure is carried out in a timely fashion.
● p9659 SI timer for the forced checking procedure
A forced checking procedure must be performed on the switch-off signal paths at least once
during the time set in this parameter.
Once this time has elapsed, an alarm is output and remains active until the forced checking
procedure 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 machinery when operational will not pose any risk to personnel. As a
consequence, the user is only made aware of the forced checking procedure that is required
using an alarm, and is requested to perform the forced checking procedure at the next possible
opportunity. This alarm does not affect machine operation.
The user must set the time interval for carrying out the forced checking procedure to between
0.00 and 9000.00 hours depending on the components used and the application (factory
setting: 8.00 hours).
The 9000 hours are only applicable for STO, SBC, SS1 functions that are integrated in the
drive and controlled via local terminals.
When using the safety-related motion monitoring functions, the value should be set to 9000
hours so that the alarm to carry out the forced checking procedure is no longer output. After
carrying out the forced checking procedure of STO, the forced checking procedure timer is
also re-started by the motion monitoring functions.
Examples for performing the forced checking procedure:
● when the drives are at a standstill after the system has been switched on.
● When the protective door is opened.
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Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated