Connection Examples for Safe Outputs
48
Bosch Rexroth AG
DOK-CONTRL-ILPSDO8****-AW04-EN-P
Rexroth Inline Module with Safe Digital Outputs R-IB IL 24 PSDO 8-PAC
7.5
Two-Channel Assignment of Safe Outputs
For two-channel assignment of the safe outputs, two adjacent outputs are always
used. This assignment is fixed and cannot be parameterized (see
Fig. 7-7
Two-channel assignment of outputs
K1 (R) and K2 (R) represent the positively driven N/C contacts for monitoring the
state of the relay (readback contacts). Connect these contacts via safe digital in-
puts. Evaluate the readback and thus the state of the switching elements in your
safe application program.
Basic specifications
Loss of safety function
•
Connect the actuator ground directly to terminal point GND of the safety mod-
ule. An external ground may not be used.
•
The failure detection time is 20 ms. This means that high pulses of this width
can occur at the faulty output (channel) in the event of an error. The two-chan-
nel assignment means that this does not result in a hazardous state.
73421006
K2 (R)
K1 (R)
K1
K2
OUT1_Ch1
GND
M
OUT1_Ch2
GND
WARNING
Actuator
Two-channel
Achievable SIL/SIL
CL/Cat./PL
SIL 3/SIL CL 3/Cat. 4/PL e
Loss of electrical and functional safety
•
To achieve the specified safety integrity level, please refer to
“Measures Required to Achieve a Specific Safety Integrity Level” on page 43
.
•
Please note that in order to achieve the specified PL, the actuator must have
a medium level of diagnostic coverage (90% to 99%) and medium MTTFd. A
high level of diagnostic coverage (> 99%) is recommended for the application
according to PL d.
•
Use actuators that can achieve the required safety integrity level.
•
Evaluate the readback contacts to achieve Cat. 3 or Cat. 4.
•
If the test pulses are disabled:
Test the outputs and external wiring by enabling the outputs at regular
intervals. The time between two tests must not exceed eight hours.
Enable the test pulses to improve device diagnostics.
If the test pulses for the actuator are faulty, they can be disabled. In
this case, test the switching capability of the outputs at regular inter-
vals.
WARNING
