Siemens SIRIUS 3RK3 Equipment Manual page 54

Overview
3.7 Safety systems - General information
This "start button" can be interfaced directly at an input of the safety relay or at a higher-level
controller. This then sends the start signal for activation of the safety outputs to the safety relay
by means of a bus signal.
Note that only authorized personnel are permitted to execute the Start command. Thus,
additional measures to prevent an unauthorized start, such as the use of a key-operated switch
as a start button, are necessary.
Evaluation of the start command or execution of one of the start types in the logic diagram can
be implemented by means of different function elements:
• Parameterization of the monitoring functions
Every sensor monitoring function (except acknowledgment buttons, two-hand operation,
and mode selector switches) has the automatic, manual and monitored start types. This type
of realization is suitable for applications with several sensors and their own command points.
• Parameterization of the output functions
Furthermore, it is possible to activate a start type at the output functions.
• Use of separate start functions
Another option is to use separate start functions. To this end, Safety ES offers start functions
for manual and monitored starting. Use of separate start functions allows you to individually
evaluate the process signals and thus to realize visualization for requesting button operation,
for example.
Start types
You will find information on the start types in the Sections:
• Automatic start (Page 54)
• Manual start (Page 55)
• Monitored start (Page 55)
Automatic start
For an automatic start, the device is started without manual confirmation, 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 inaccessible danger zones can use the automatic start function if this
does not pose any risk.
Note
An automatic start is not permitted for EMERGENCY STOP devices.
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SIRIUS 3RK3 Modular Safety System
Equipment Manual, 07/2020, NEB926253002000/RS-AC/006