BECKHOFF TwinSAFE - Manual (Page 15)

Circuit examples
Application Guide TwinSAFE 13
2.2 ESTOP function variant 2 (Category 3, PL d)
The emergency stop button is connected via two break contacts to an EL1904 safe input terminal. The
testing of the two signals is activated. The signals are not tested for discrepancy. The restart and the
feedback signal are wired to standard terminals and are transferred to TwinSAFE via the standard PLC.
The contactors K1 and K2 are connected in parallel to the safe output. Current measurement and testing
of the output are active for this circuit.
2.2.1 Parameters of the safe input and output terminals
EL1904
Parameter Value
Sensor test channel 1 active Yes
Sensor test channel 2 active Yes
Sensor test channel 3 active Yes
Sensor test channel 4 active Yes
Logic channel 1 and 2 Single Logic
Logic channel 3 and 4 Single Logic
EL2904
Parameter Value
Current measurement active Yes
Output test pulses active Yes