Measures To Achieve A Specific Safety Integrity Level - Bosch Rexroth IndraControl S20 Manual

DOK-CONTRL-S20*PSDO*8*-AP02-EN-P
IndraControl S20 Module With Safe Digital Outputs S20-PSDO-8/3
7.3

Measures to achieve a specific safety integrity level

SIL, SILCL
Performance level
Category
The safety integrity level (SIL, SILCL, category, and performance level) that can be
achieved is specified for each connection example.
Use the standard to determine the probability of failure in your appli-
cation according to IEC 61508 (SIL) and EN 62061 (SILCL).
Safety integrity
SIL 2/SILCL 2
SIL 3/SILCL 3
Fig. 7-3 PFD and PFH depending on the SIL/SILCL
Use standard EN ISO 13849-1 to determine the performance level.
The categories are achieved with the following measures:
Measure
Use proven and basic safety principles according to
EN ISO 13849-2.
Use qualified actuators: see
trolled devices" on page 13.
Please note that mechanical failure of the switching device can
result in the loss of the safety function.
Prevent the welding of contacts on the connected contactors or
safety relays with protection against overcurrent and surge
voltage.
Please note that a single error can result in the loss of the safety
function between tests.
Make sure that the external wiring is tested by the machine
controller on machine startup and at suitable intervals. This test
must detect the loss of the safety function.
Make sure that in the event of an error the module shuts down
safely or generates a warning (optical and/or audible) depend-
ing on the application.
Please note that all errors that cannot be detected can result in
the loss of the safety function. Take measures to prevent these
errors (e.g., protected cable installation or double insulation).
Observe the notes in the following tables.
Please take into consideration errors with a common cause.
Make sure that a single error does not result in the loss of the
safety function.
Test the shutdown capability of the actuators at adequate and
regular intervals for test pulses that are disabled.
An accumulation of errors must not result in the loss of the
safety function. Following the third error, evaluation can be
aborted if the probability of further errors occurring is low.
Bosch Rexroth AG
Connection examples for safe outputs
PFD
-2
1% of 10
-3
1% of 10
"Requirements for actuators/con-
35/82
PFH
-6
1% of 10
-7
1% of 10
Cat. 2 Cat. 3 Cat. 4
x x x
x x x
x x x
x x x
x
x
x
x x
x x
x
x x
x