What Is a REX? (Request-to-Exit) Explained for Access Control Systems
In the access control and commercial locksmith industry, REX stands for Request-to-Exit. While it may seem like a small component in an access control system, it plays a critical role in life safety, system logic, and proper door operation. Understanding what a REX is—and when it’s required—can help prevent nuisance alarms, damaged hardware, and failed inspections.
What Does a REX Do?
A Request-to-Exit (REX) device tells an access control system that someone is intentionally exiting through a controlled door. When activated, the REX temporarily:
- Unlocks the door
- Bypasses door position alarms
- Prevents forced-door alerts
- Allows free egress without credentials
In short, a REX allows occupants to exit safely without triggering alarms or fighting against electrified locking hardware.
Without a REX, opening a secured door from the inside can cause forced-door alarms, maglock resistance, inaccurate event logs, or even hardware damage over time.
Why REX Is Important in Commercial Doors
Most access control systems are designed to control entry, not exit. However, building and fire codes require doors to allow free and immediate egress.
A properly installed REX ensures:
- Compliance with life-safety requirements
- Smooth operation of maglocks and electrified strikes
- Accurate access control reporting
- Fewer service calls and troubleshooting issues
This is especially important on doors using magnetic locks, electrified strikes, delayed egress systems, or alarmed exit devices.
Common Types of REX Devices
1. REX Motion Sensors (PIR)
Motion-based REX sensors are typically mounted above the door and detect movement when someone approaches from the secure side.
- Pros: Hands-free operation, clean appearance
- Cons: Can false-trigger if improperly placed
2. REX Push Buttons
These are physical buttons mounted near the door, usually labeled “PUSH TO EXIT.”
- Pros: Very reliable, minimal false activations
- Cons: Requires intentional user action