GFK-2956A  November 2017  53 
7.7  Dual-channel Safety Door Monitoring with Magnetic Switch, 
Automatic Reset and Emergency Stop 
 
•  Dual-channel monitoring PDF-M (as per 
EN 60947-5-3) 
•  Cross-connection detection 
•  Automatic reset 
•  Monitoring of external contactors (EDM) 
 
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 or the safety door is opened, the EP-19xx switches off 
the 24-V supply for the modules (switchable 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 the safety door as well 
as a cross-circuit in their 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: 
•  Emergency stop button is unlocked 
•  Safety door is closed 
•  Feedback circuit (NC contacts of K3 and K4) is closed 
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. To reset the system, press the reset button within 0.1 to 2 s after 
switching on the power supply, even when automatic reset is used.