Siemens SIRIUS 3RK3 - Page 55

WARNING
Restarting the system
Can Cause Death, Serious Injury, or Property Damage.
The start type depends on the risk assessment. For PL e n accordance with EN ISO 13849‑1 as
well as SIL 3 in accordance with IEC 61508, the monitored start must be used in the case of
EMERGENCY STOP, for example. For other safety sensors/functions, the need for a monitored
start command depends on the risk assessment.
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.
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Figure 3-6 Start function "Manual start"
Note
A blocked start button is not detected in the case of this start type. Thus, for example, a
disruption of the signal can trigger an undesirable start. The manual start is therefore not
suitable for PL e in accordance with EN ISO 13849-1 or SIL 3 in accordance with IEC 61508.
WARNING
Restarting the system
Can Cause Death, Serious Injury, or Property Damage.
The start type depends on the risk assessment. For PL e n accordance with EN ISO 13849‑1 as
well as SIL 3 in accordance with IEC 61508, the monitored start must be used in the case of
EMERGENCY STOP, for example. For other safety sensors/functions, the need for a monitored
start command depends on the risk assessment.
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 the signal sequence of the START
button. The output is not activated until the START button is opened again and its operating
duration was within the valid time window (0.15 s to 2 s). This means that the START button
cannot be bypassed (misuse). For PL e n accordance with EN ISO 13849‑1 as well as SILCL 3 in
accordance with EN 62061, monitored start must be used in the case of EMERGENCY STOP. For
Overview
3.7 Safety systems - General information
SIRIUS 3RK3 Modular Safety System
Equipment Manual, 07/2020, NEB926253002000/RS-AC/006 55