Siemens SIRIUS 3SK1

4.3.7 Automatic start
For an automatic start, the device is started without manual con󹪝rmation, but only after the
input image has been checked and a positive test of the safety relay has been conducted. This
function is also known as dynamic operation and is not permissible for EMERGENCY STOP
devices. Safety devices for prohibited danger zones (e.g. position switches, light arrays, safety
shutdown mats) can use the automatic start function if this does not pose any risk.
Note
An automatic start is not permitted for EMERGENCY STOP devices.
Information about start response in the system con󹪝guration of 3SK1 Advanced units can be
found in the chapter "Explanations of device function (Page 176)".
4.3.8 Manual start
For a manual start, the device is started by operating the START button, but only after the input
image has been checked and a positive test of the safety relay has been conducted. On a manual
start, the START button is not monitored for correct operation, a positive edge of the START
button is su󹪟cient for starting.
Note
The "manual start" function is only available with the 3SK1111 safety relays (slide switch at
Autostart position).
Note
Manual start is not permitted for EMERGENCY STOP devices.
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Figure 4-3 "Manual start" start function
4.3.9 Monitored start
For a monitored start, the device is started by operating the START button, but only after the
input image has been checked and a positive test of the safety relay has been conducted.
Contrary to the manual start, the monitored start evaluates a signal change of the START
button. This means that the START button cannot be bypassed (misuse). For PL e (ISO 13849-1)
as well as SIL 3 (IEC 62061), the monitored start must be used in the case of EMERGENCY STOP.
For other safety sensors/functions, the necessity for a monitored start command depends on the
risk assessment.
Safety systems - General information
4.3 Basic terminology
SIRIUS 3SK1 Safety Relays and 3RQ1 Positively-Driven Coupling Relays
46 Equipment Manual, 05/2021, A5E02526190021A/RS-AE/005