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.