Siemens SINUMERIK 840D sl Function Manual page 44

Safety Functions Integrated in the Drive
4.1 General information about SINAMICS Safety Integrated
Shutdown paths
Two independent shutdown paths are available. All shutdown paths are low active.
Thereby ensuring that the system is always switched to a safe status if a compo-
nent fails or in the event of cable breakage.
If an error is discovered in the shutdown paths, the "safe standstill" function is acti-
vated and a system restart inhibited.
Two-channel monitoring structure
All the main hardware and software functions for Safety Integrated are imple-
mented in two independent monitoring channels (e.g. shutdown signal paths, data
management, data comparison).
The two drive monitoring channels are implemented using the following compo-
nents:
S Control Unit
S Motor Module belonging to a drive
Forced checking procedure and test of the shutdown paths
The forced checking procedure of the shutdown paths is used to detect errors in
the software and hardware of the two monitoring channels as quickly as possible
and is automatically carried-out when the "safe standstill" function is activated/de-
activated.
To fulfill the requirements of EN 954–1 regarding timely error detection, the two
shutdown paths must be tested at least once within a defined time to ensure that
they are functioning properly. For this purpose, the forced checking procedure
must be either initiated manually by the user or automatically as part of the pro-
cess.
A timer ensures that the forced checking procedure is carried-out as quickly as
possible.
S p9659
The forced checking procedure of the shutdown paths 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 the
forced checking procedure is carried-out.
The timer returns to the set value each time the "safe standstill" function is deacti-
vated.
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 operator that a forced checking
procedure is due and request that this be carried-out at the next available opportu-
nity. This alarm does not affect machine operation.
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SINUMERIK 840D sl/SINAMICS S120 SINUMERIK Safety Integrated (FBSI sl) – 03.2006 Edition
Safety Integrated timer for forced checking procedure
© Siemens AG, 2006. All rights reserved
03.06