Informational
What Is a Request-to-Exit Sensor?
Explainer Guide
A request-to-exit sensor is a device that detects someone leaving and tells the access system to release the door without needing a credential.
What It Means
A request-to-exit sensor, often shortened to REX, is used on the safe side of a door to trigger release when someone approaches or activates the exit path. Instead of pressing a simple button, the release can be triggered by the sensor detecting movement or another exit condition configured by the installer.
| Question | Exit Button | Request-to-Exit Sensor |
|---|---|---|
| How release is triggered | Manual push | Sensor or automatic detection path |
| Typical fit | Straightforward doors | Doors where automatic or higher-flow egress makes more sense |
| Main design question | Is a simple manual release enough? | Is a more automatic exit method needed? |
How It Fits in a Real Installation
REX devices are useful where a simple push button is not the best operational answer, such as doors with higher throughput or sites that want a more automatic exit experience. They still need to be designed around the actual door and safe egress requirements.
Why It Matters
It matters because egress is part of the system design, not an afterthought. The installer has to decide how the door will release from the safe side and whether a manual button or a sensor-driven exit path is more sensible.
Common Misunderstandings
A common misunderstanding is assuming every access-controlled door should use the same type of exit method. The right exit path depends on the door, traffic flow, and how the site actually operates.
Where to Go Next
Read the hardware guide next if you want to see how REX devices, exit buttons, lock choice, and door contacts fit together.
Relevant SecurityWholesalers Product Areas
- Access Control – The main category for controllers, readers, credentials, locks, and supporting hardware.
- Door Strikes – Often the cleanest answer for hinged commercial doors when the latch and frame suit the hardware.
- Door Locks – Helpful when comparing maglocks, monitored locks, and other locking paths.
Related Guides in This Series
- What Is an Exit Button?
- Strikes, Maglocks, Exit Buttons, and Door Sensors
- How Does Door Access Control Work?
Source References
Frequently Asked Questions
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What does a request-to-exit sensor mean in plain English?
A request-to-exit sensor tells the system to release the door when someone is leaving, usually without a credential.
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Where does a request-to-exit sensor fit in a real installation?
REX devices fit doors where a simple exit button is not the most practical egress method.
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Why does a request-to-exit sensor matter to a buyer or installer?
It matters because safe exit design is a core part of access control, not an optional extra.
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What do people usually get wrong about a request-to-exit sensor?
The best exit method depends on the door and workflow, not a universal rule.
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When should a site move beyond the basic version of this?
A site moves beyond the basic discussion when it is comparing several egress methods alongside lock type and door monitoring.
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Which related guide should someone read next?
Read the hardware guide next for the full door-hardware picture.