DS160 REX Sensor: Complete Specification, Wiring and Installation Guide

The DS160 REX sensor from Bosch Security is a passive infrared request-to-exit detector built exclusively for commercial access control applications. Stocked at American Locksets in the electronic hardware section, the DS160 REX detects a person approaching an exit door and automatically signals the access control panel to suppress the door alarm and release the electric strike without any button press from the exiting person. It covers an 8-foot by 10-foot PIR detection zone, carries UL 294 listing as an access control device, and includes Bosch's exclusive Sequential Logic Input (SLI) technology — a security feature not found in any other REX device on the market.

Before getting into specifications, understanding what request-to-exit actually does in the system prevents the most common wiring and specification errors on access control projects.

What Request to Exit (REX) Means and Why Every Controlled Door Needs One

Request to exit is the signal sent to an access control panel to indicate that a legitimate exit is occurring through a controlled door. Every access control system secures a door from unauthorized outside entry. But every controlled door also needs to manage exits from the inside. Without a REX device, every time a person opens the door from the exit side without using a credential, the panel has no way to distinguish that from a forced entry and triggers an alarm.

The REX device solves this by sending a signal to the panel before the door opens. The panel receives that signal, suppresses the door alarm for a configured shunt delay period, and releases the lock or electric strike. The person exits. The door closes. The system returns to normal monitoring with no false alarm logged.

Without a properly configured REX device, either every legitimate exit generates a false alarm, or the monitoring is suppressed universally, which defeats the security purpose entirely.

DS160 vs DS161: Which Color to Specify

The DS160 and DS161 are functionally identical in every way. Same PIR sensor, same SLI technology, same coverage pattern, same wiring, same UL listings. The only difference is enclosure color.

DS160: Light gray. Specified for white and light-colored walls and frames where gray blends with surrounding hardware.

DS161: Black. Specified for dark finishes, black door frames, and modern commercial interiors.

Order the color that matches the wall and hardware finish on the door schedule. Both are available through the electronic hardware section at American Locksets.

What Sequential Logic Input (SLI) Does and Why It Matters

SLI is the technical feature that separates the DS160 REX sensor from every standard PIR REX device. A standard PIR REX sensor triggers its relay output whenever it detects any infrared motion change within the coverage zone. That creates two security vulnerabilities:

An object pushed under the door, slid through the door gap, or passed through the coverage zone from the secure entry side can trigger a standard PIR REX relay and release the door for unauthorized entry.

A person on the access-controlled entry side reaching into the detection zone can trigger a standard sensor and unlock a door they have no credential to use.

The DS160's SLI terminal requires a second device to arm the detector before PIR detection can fire the relay output. The SLI input connects to a second PIR detector, a card reader output, or the access control panel. Until the arming signal is present, PIR detection alone cannot release the door.

In dual-detector sequential configuration, a second sensor aims at the approach zone further from the door. The first sensor arms the DS160. The person walks toward the door, triggering the arming sensor first and then the DS160 in the correct directional sequence. An object pushed through the door cannot replicate a person walking toward it in the correct order.

In remote lockout configuration, Terminal R on the DS160 connects to the access control panel. When the panel closes that contact, the DS160 disables after a 10-second delay and stops generating REX outputs. This is the correct setup for lockdown scenarios where the panel needs to override all REX functionality from a central command.

Complete Confirmed Specifications

All figures confirmed from the official Bosch DS160 data sheet and installation guide:

Detection:

• PIR coverage: 8 feet by 10 feet (2.4m by 3m)

• Pattern: Wrap-around coverage with precise pattern control

• Pointability: Internal vertical lens adjustment to direct zone toward door approach path

• Mounting: Surface mount on wall or ceiling, indoor use only

Relay behavior:

• Latch time: Adjustable up to 64 seconds

• After door opens and closes: Relay drops 2 seconds after door close, regardless of latch timer setting

• After activation without door opening: Relay drops after 10 seconds

Settings:

• Timer modes: Resettable (accumulative) or non-resettable (counting), DIP switch selectable

• Fail-safe and fail-secure relay modes: Field selectable

• Sounder volume: Adjustable

• Activation LED: On or off, DIP switch selectable

Terminals:

• Terminal R: Remote disable input. Normally-closed contact from controller disables REX after 10-second delay

• Terminal D: Door position switch input (normally closed) for door monitor sounder function

Compliance:

• UL 294 listed: Access control device (USA)

• ULC-S319 listed: Class I (Canada), requires ULC-listed compatible system

• NFPA 101: Requires separate manual release device directly interrupting lock power, independent of access control electronics

Physical:

• Dimensions: 6.75 inch by 1.8 inch by 1.75 inch

• Indoor use only

• Not for standalone operation; must connect to a listed compatible access control system

• Not for burglar alarm system connection

The 2-Second Relay Drop: The Security Detail Every Installer Should Know

This behavior is confirmed in the Bosch installation guide and is absent from every product listing in the current top 20 search results. It matters significantly for how the system behaves after the door cycles.

When the DS160 REX triggers the relay and the door opens and then closes, the relay drops 2 seconds after the door closes regardless of how long the configured latch timer is set.

Most installers expect the relay to hold for the full configured latch time, say 20 or 30 seconds, even after the door has already closed. The DS160 does not work that way. Once the door position switch on Terminal D confirms the door is closed, the relay drops 2 seconds later. This eliminates the window where a second person could pull the door open again during the remaining latch time.

This also means Terminal D wiring to the door position switch is functionally required for the DS160 to deliver its full security performance. Without Terminal D connected, the sensor cannot detect that the door has closed and cannot execute the 2-second drop.

Similarly, if the DS160 fires its relay but the door never opens, the relay drops after 10 seconds. This covers scenarios where motion triggers the REX and the person does not follow through the door.

Fail Safe and Fail Secure Mode Selection

The DS160 REX supports both fail-safe and fail-secure relay modes via DIP switch selection. The mode must match the lock or electric strike configuration on the door.

Fail-safe mode: The relay stays in its normal state when power to the DS160 is lost. Used with fail-safe electric strikes that default to unlocked on power loss. The door opens freely if the sensor loses power.

Fail-secure mode: The relay changes state when power is lost. Used with fail-secure electrified locks that remain locked on power loss. The door stays secured if the sensor loses power.

Specifying a fail-safe DS160 on a door with a fail-secure electrified mortise lock creates a configuration conflict that surfaces during the first power loss test on site. Confirm both the DS160 mode and the lock or strike function match before commissioning. For a complete breakdown of fail-safe versus fail-secure and which function belongs on which opening, see the fail safe vs fail secure guide on this site.

Wiring the DS160 REX in a Standard Access Control Installation

Power supply: 12VDC or 24VDC. Confirm the panel auxiliary output voltage before ordering.

REX output to panel: Connect the DS160 relay output to the REX input terminal on the access control panel. When the PIR detects valid exit motion (with SLI confirmed if configured), the relay closes. The panel receives the REX signal, suppresses the door alarm, and releases the electric strike or lock for the configured shunt delay period.

Terminal D (door contact): Connect the normally-closed door position switch to Terminal D. This enables the 2-second relay drop after door close and activates the door monitor sounder function if a door is propped open beyond the configured time.

Terminal R (remote disable): Connect to the access control panel output when SLI lockout or remote disable is needed. When the panel closes this contact, the DS160 disables after a 10-second delay. It re-enables when the contact opens.

For openings with electric strikes, the REX output connects to the strike shunt input or panel REX terminal. For openings with electrified mortise locks, the REX output goes to the panel REX terminal for full exit event logging. All wiring must comply with ANSI/NFPA 70 National Electrical Code. Direct connection to a keypad is not permitted; a listed compatible access control system is required.

Mounting the DS160 REX for Reliable Coverage

Position: Mount just above the door on the hinge side, lens pointed down and slightly outward toward the exit approach path. This places the 8-foot by 10-foot coverage zone directly in front of the door from the exit side without including the secure entry side.

Internal lens adjustment: Adjust the vertical lens position inside the enclosure to direct coverage toward the approach path. After mounting, walk a cardboard sheet through the detection zone from different angles to confirm where the sensor triggers and verify the zone does not extend through the door to the entry side.

Ceiling mount: For walls with wainscoting, tile, or restricted mounting conditions, ceiling mount places the DS160 directly above the door aimed at the approach path below. More precise zone verification is needed after ceiling installation because the detection shape changes at ceiling height.

Dual-detector SLI placement: When using sequential dual-detector REX, mount the arming detector 6 to 8 feet from the door and the triggering DS160 2 to 3 feet from the door. A person walking toward the door activates the arming sensor first and the DS160 second, in the correct sequence. Motion entering the zone from the wrong direction cannot replicate this ordered sequence.

NFPA 101 and ADA Requirements

NFPA 101 Life Safety Code: Requires that secured doors on required means of egress have a manual release device that directly interrupts power to the lock, independent of access control system electronics. The DS160 REX output alone does not satisfy this requirement. A separate manual release device, typically a push-to-exit button wired to directly cut lock power, must be present alongside the DS160 on egress path applications. For egress-rated exit hardware options on panic-device-equipped doors, see the exit hardware section on this site.

ADA reach range: Push-to-exit buttons on accessible routes require mounting between 15 and 48 inches above the finished floor for forward reach. PIR-based REX sensors including the DS160 require no physical interaction from the user, which eliminates the ADA reach range requirement that applies to push buttons. On accessible routes where wall-mount height constraints are a concern, PIR-based REX is the ADA-compliant choice.

Why American Locksets for DS160 REX Projects

The most consistent DS160 installation problems trace to three errors: Terminal D not wired to the door position switch, fail-safe mode selected on a fail-secure lock, and the SLI not configured when the installation required it for security. All three produce problems that get diagnosed as access control panel or lock failures before anyone checks the REX sensor settings.

American Locksets has supplied access control hardware from authorized distribution since 2001. The Bosch DS160 (light gray) and DS161 (black) are stocked through the electronic hardware section alongside electric strikes, electrified locks, power supplies, and door control accessories. For complete door hardware packages where DS160 REX sensors install alongside commercial locks on the same door schedule, everything ships from one authorized dealer order with same-day shipping from multiple US warehouses.

Call 877-471-4870 with the access control panel voltage, door type, and whether SLI configuration is required. We confirm the right DS160 setup before the order ships.

Conclusion

The DS160 REX sensor delivers passive infrared request-to-exit detection with an 8-foot by 10-foot coverage zone, Bosch's exclusive Sequential Logic Input that prevents unauthorized door releases from object slides and wrong-direction motion, and a built-in 2-second relay drop after door close that eliminates the unauthorized re-entry window present on standard PIR REX sensors. Fail-safe and fail-secure modes are field selectable by DIP switch. Terminal D wiring to the door position switch is required for full security performance. Terminal R enables remote disable by an access control panel or secondary device. The DS160 is light gray; the DS161 is the functionally identical black variant. Both are UL 294 listed for indoor access control use. American Locksets stocks both from authorized Bosch distribution with same-day shipping. Call 877-471-4870 or visit the electronic hardware section to confirm the right DS160 REX configuration for the project.

Frequently Asked Questions

What is the DS160 REX sensor used for? 

The DS160 REX is a PIR detector that signals access control panels to release controlled doors for legitimate exits, suppressing door alarms without requiring a button press.

What does SLI do on the Bosch DS160? 

Sequential Logic Input requires a second device to arm the sensor before PIR detection triggers the relay, preventing object-slide attacks and wrong-direction motion from releasing the door.

What is the difference between DS160 and DS161? 

Color only. DS160 is light gray. DS161 is black. Specifications, wiring, SLI, coverage, and UL listings are identical.

Why does the DS160 relay drop after 2 seconds when the door closes?

 The relay drops 2 seconds after the door position switch confirms the door is closed, eliminating the re-entry window that would exist if the full latch timer continued running after door close.

Does the DS160 support fail-safe and fail-secure? 

Yes. Both modes are field selectable via DIP switch. The selected mode must match the electric strike or electrified lock configuration on the same door.

Is Terminal D wiring required on the DS160?

 Yes, for full security performance. Terminal D connects to the door position switch and enables the 2-second relay drop after door close and the door monitor sounder function.

Where can I buy the Bosch DS160 REX sensor? 

American Locksets stocks both DS160 (gray) and DS161 (black) at americanlocksets.com/electronic-hardware. Call 877-471-4870 to confirm configuration before ordering.

 

Published by the American Locksets Hardware Team. Authorized Dealer, Est. 2001, Monroe, NY.