Lesson 1.4: REX Buttons and Sensors

⚡ The Logic (Mermaid)

flowchart LR
    INPUT["REX Input 
on Door Terminal"]

    subgraph DEVICES["near Exit side of Door "]
        direction TB
        PB("Push Button")
        PIR("Request-to-Exit
PIR")
    end

    ZV["0V 
on Door Terminal"]

    INPUT --- PB --- ZV
    INPUT --- PIR --- ZV

Hardware Landmark: Request-to-Exit (REX) PIR

!300
Above: A hands-free PIR REX sensor typically mounted above the door on the secure side.

🧠 The Concept

A REX (Request to Exit) device tells the system that someone is leaving from the secure side. This prevents "Door Forced" alarms. PIR REXs are hands-free, while Push Buttons are manual. In Inner Range, these are typically wired as supervised zone inputs.

🛠️ Hands-on Steps

PIR Placement: Mount the PIR REX so it "sees" the person before they reach the handle, but not so wide that it triggers from people walking past the door.
Timed Release: Configure the "REX Release Time" in the software (usually 5-10 seconds).
Supervision: Use resistors (Lesson 1.8) to ensure the REX cable hasn't been cut.

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