GE RSTi-EP - Dual-Channel Emergency Stop Monitoring

Chapter 7. Example Applications
GFK-2956A November 2017 41
Example Applications
7.1 Dual-channel Emergency Stop Monitoring
Achievable safety rating
Cat. 4
DIN EN ISO 13849-1
PLe
DIN EN ISO 13849-1
SIL3
IEC 62061/61508
Stop category
0
EN 60204-1
Features
• Dual-channel monitoring
• Cross-connection detection
• Manual reset
• Monitoring of external contactors (EDM)
Safety sensor/operating
mechanism
Emergency stop button
Notes
Autostart is possible if the NC circuits from
K3 and K4 are attached to 3.3 and 3.4.
Note: All example applications shown are proposals without warranty. In any case the operator has
to perform a safety review of the entire site.
When the emergency stop button is pushed, the EP-19xx switches off the 24-V supply for the
modules (refer to the section, General Contact Information) within the safety segment and thus also
contactors K3 and K4. The failure of a switching element in the emergency stop button or a cross-
circuit in its supply lines does not result in the failure of the emergency stop mechanism and is
detected within the fault-reaction time.
The EP-19xx switches on the 24-V supply for the modules within the safety segment if:
• the emergency button is unlocked
• and the feedback circuit (NC contacts of K3 and K4) is closed
• and the start push button has been pushed and released again.
Contactors K3 and K4 are controlled by the PLC and can switch on as soon as the EP-19xx has
switched on the 24-V supply.