Siemens SIRIUS 3RK3 - Errors and System Callbacks; Connection Rules

Description of the software
6.6 Logic diagram
Modular Safety System 3RK3
156 System Manual, 10/2008, 926 2530-02 DS 02
6.6.4.17 Errors and system callbacks
If you execute impermissible actions when working with the logic diagram, error messages
are displayed.
Meaning of the error messages and system callbacks
Error message Meaning
It is not permitted to connect inputs to each other. You have tried to interconnect two inputs. This is not
permitted. It is only possible to connect one input to one
output and vice versa.
Connection of two outputs not possible. You have tried to interconnect two outputs. This is not
permitted. It is only possible to connect one input to one
output and vice versa.
This connection is prohibited. You have tried to create a connection that is not possible.
Inputs and outputs cannot be interconnected at will (see
above).
Inputs can only be used once. You have tried to connect to an input that is already
assigned. An input can only be the output point of one
connection.
Feedbacks are not permissible. You have tried to establish a connection between outputs
and inputs with the same function. Please note that this
must not be a direct connection, the feedback can be
established across several functions. Please check the
signal flow.
6.6.5 Connection rules
Due to the hardware properties or safety regulations there are connection rules which must
be checked or monitored when functions are edited.
General
● Signals must not be connected recursively, i.e. "backwards".
● Non-fail-safe input signals (= standard inputs) can only be added to a safety circuit if they
are ANDed with a safe signal.
● Input terminals (fail-safe/non-fail-safe) can only be used once as an input (input cell or
monitoring functions).
● Output terminals (fail-safe/non-fail-safe) can only be used once as an output (output cell /
switching output), although each output terminal can also be used once as an input
terminal with an input cell.
(Comment: Output terminals controlled by the logic can also not be used, i.e. the output
terminal must not be interconnected to an output cell or a switching output.)