Siemens SINUMERIK 840D sl Function Manual page 278

Connecting sensors and actuators
8.5 Safe programmable logic
The description is provided in the following:
Three shutdown inputs
E1 to E3
Two acknowledge inputs
Q1 and Q2
Three timer initialization
values
TI1 to TI3
One timer limit value TM1 Defines the maximum time that the shutdown inputs E1 to E3 may have been at a 0 signal level
Four output values A0 to
A3
Initialization in the part program
The connections for the function block are defined when initialized. The input and output
quantities of the function block are assigned to the required system variables ($A_MARKERSI,
$A_INSE, $A_OUTSE,...). The following functions must be called:
SIRELIN: This language command assigns the input quantities Q1, Q2, E1, E2 and E3 to the
safety relay x (x = 1...4). The return value contains the number of the first incorrect parameter;
a value of 0 indicates that the parameter assignment is correct.
Syntax: SIRELIN (x,status,"Q1","Q2","E1","E2","E3")
The transfer parameters Q1 to E3 are strings and must therefore be entered in quotation marks
(" "). The following system variables are permissible as input quantities:
$A_MARKERSI[ ]
$A_INSE[ ]
$A_INSI[ ]
$A_OUTSE[
]$A_OUTSI[ ]
E2 and E3 are optional. If these parameters are not entered, the relevant inputs are set to "1"
(static signal).
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If one of these inputs is set to 0, then direct output A0 is set to 0. Outputs A1 to A3 switch with
the delay of timer 1-3. If one of these inputs is not used, then it is internally set to "1" as static
signal.
One of these inputs must also be used to initiate test operation of the safety relay (forced checking
procedure).
Q1 must be supplied with the signal from the real acknowledge button.
Q2 is only used for the forced checking procedure. The software relay itself does not have to be
subject to a forced checking procedure. However, if the Emergency Stop function is executed
via this, and if external actuators have to be subject to a forced checking procedure, if the relay
drops-out during the Emergency Stop test, then it can be acknowledged using Q2 (in a defined
time window, refer to TM1). This input must also be connected with a safety system variable
(even if the signal is not used) - preferably with a $A_MARKERSI - in order to detect that this
acknowledge signal is available as steady-state signal in the crosswise data comparison with the
PLC. The associated comparison data in the PLC must have a steady-state 0 signal level (error
detection using different states of the particular SPL marker for the PLC and NCK).
The times after which outputs A1 to A3 are switched to 0 at a negative edge in output signal A0
are defined here.
so that they can still be acknowledged using Q2. Q2 should only be used for the internal safety
relay test. It is not permissible that Q2 is used to acknowledge a "real" shutdown.
A0 supplies the result of ANDing E1 to E3 without any delay. Outputs A1 to A3 supply the same
result for positive edges of A0; for negative edges, the results are delayed by the timer initialization
TI1 to TI3 (switch-out delay).
A0 to A3 do not produce a result after booting until an acknowledgment has been received via
Q1.
Function Manual, 12/2017, 6FC5397-4BP40-6BA1
Safety Integrated