Delta Controls
Access Door Module
Page 19 of 26
Type 4 EOL Circuit (Normally Open Contact)
This EOL Circuit is used to monitor/supervise a Normally Open contact, to indicate Trouble when there is
either a Short Circuit (contact bypassed) or an Open Circuit (wires cut). This supervised circuit gives the most
feedback on the input’s condition, along with Type 3 for Normally Closed contacts.
When using the Type 3 or Type 4 EOL Circuit and a Request to Exit button that has a single pole switch, make
sure that the 10K Ohm resistor is on the input leg of the circuit, not the ground side of the circuit, or the Door
Lock and/or Request to Exit status may not work properly, as shown below.
Contact
Door Contact
Voltage Range
Type 4 - Normally Open Contact
Switch Closed
Switch Open
Cicuit Open
Circuit Short
Door Closed
Door Open
Trouble (open)
Trouble (shorted)
1.17 - 2.89
2.90 - 4.02
4.02 - 5.00
0.00 - 1.16
10
KOhm
2
1
Input
10
KOhm
N.
O.
Request to Exit
Request to Exit
Door Close
Trouble (open)
Trouble (shorted)
