Sentinel Reader Family

Key Features

Mobile-ready by default, including Apple's Enhanced Contactless Polling (ECP) to support credentials in Apple Wallet
Google Wallet and third-party mobile credential support via BLE 5.0
13.56 MHz NFC: ISO 14443A/B, ISO 15693, MIFARE DESFire EV1/EV2/EV3, MIFARE Classic, MIFARE Plus, FeliCa
125 kHz legacy support on S200 models: HID Proximity, EM4100, AWID, Indala
OSDP v2 secure channel with AES-128 encryption over RS-485
Wiegand 26-bit and 34-bit output for backward compatibility
IP65-rated enclosure for indoor and sheltered outdoor installations
Tri-color LED and piezo buzzer for configurable audio/visual feedback
Tamper switch with active-low output
Field-upgradable firmware via OSDP file transfer

The Sentinel series is Offset Security's line of physical access control readers. Designed from the ground up for mobile credential support, every Sentinel reader ships with Apple ECP and BLE 5.0 enabled out of the box.

The S100 series is a compact reader suitable for mullion-mount door installations or any surface with limited space. The S200 series adds 125 kHz legacy credential support for sites that need to run both proximity cards and modern NFC/mobile credentials during a migration period.

Both series offer keypad variants (S100K, S200K) for deployments that require PIN-based multi-factor authentication. The keypads are backlit and support configurable layouts.

All Sentinel readers use OSDP v2 as the primary controller interface. The secure channel implementation encrypts all reader-to-panel communication with AES-128, preventing credential interception at the wire level. Wiegand output is also available for backward compatibility with older panels.

Firmware updates are delivered over OSDP file transfer, so readers can be updated remotely without physical access to the device.

Security Architecture

Multi-layered security — hardware secure element, encrypted communication, and tamper detection work together to protect credential data in transit and at rest.
EAL4+ Secure Element — on-board secure element stores cryptographic keys and handles credential processing in a certified isolated environment.
OSDP v2 Secure Channel — AES-128 encrypted, bidirectional communication between reader and access control panel over RS-485.
Tamper detection — hardware tamper switch triggers an active-low signal to the controller when the reader enclosure is opened or removed from the wall.
Firmware integrity — signed firmware images verified before installation. Updates delivered over OSDP file transfer for remote management.

Management & Configuration

Configure reader parameters via OSDP commands from the access control panel
Update firmware remotely using OSDP v2 file transfer
Customize LED color sequences and buzzer patterns per access event
Set BLE read range from 0.5 m to 8 m via configuration command
Enable or disable individual credential technologies per reader
Deactivate legacy 125 kHz credentials on a per-reader basis to enforce migration deadlines

Specifications

Specification	S100	S100K	S200	S200K
Part Number	OS-SEN-S100	OS-SEN-S100K	OS-SEN-S200	OS-SEN-S200K
2.4 GHz (Bluetooth) Credential Compatibility	BLE 5.0 — Apple Wallet (ECP), Google Wallet, third-party mobile credentials
13.56 MHz (NFC) Credential Compatibility	ISO 14443A/B, ISO 15693, MIFARE Classic, MIFARE DESFire EV1/EV2/EV3, MIFARE Plus, FeliCa, NTAG 21x Apple Wallet credentials via Enhanced Contactless Polling (ECP)
125 kHz Credential Compatibility	—	—	HID Proximity, EM4100/4102, AWID Proximity, Indala Proximity
Apple Enhanced Contactless Polling (ECP)	Yes	Yes	Yes	Yes
Typical Read Range¹	NFC (13.56 MHz): 1.6 to 4 in (4 to 10 cm) 125 kHz (S200 series): 2.4 to 4 in (6 to 10 cm) BLE: configurable 0.5 to 8 m (1.6 to 26 ft)
Communication Interface	OSDP v2 (RS-485, AES-128 secure channel) · Wiegand 26/34-bit
Keypad	No	Yes (2 × 6 layout)	No	Yes (3 × 4 layout)
Mounting	Mullion-mount or flat surface mount; single-gang adapter plate available		Single-gang electrical box; slotted mounting plate; back-box spacing
Dimensions (W × H × D)	1.77 × 4.78 × 0.77 in (45 × 121.5 × 19.5 mm)	1.78 × 4.79 × 0.85 in (45 × 121.5 × 21.5 mm)	3.15 × 4.78 × 0.77 in (80 × 121.5 × 19.5 mm)	3.16 × 4.79 × 0.85 in (80 × 121.5 × 21.5 mm)
Weight	Pigtail: 3.35 oz (95 g) Terminal: 2.65 oz (75 g)	Pigtail: 3.88 oz (110 g) Terminal: 3.17 oz (90 g)	Pigtail: 4.94 oz (140 g) Terminal: 4.23 oz (120 g)	Pigtail: 5.64 oz (160 g) Terminal: 4.94 oz (140 g)
Color	Black enclosure with brushed silver trim baseplate
Operating Voltage	12 V DC
Current Draw²	NSC³: 60 mA Peak: 250 mA Avg: 70 mA IPM⁴: 45 mA	NSC³: 65 mA Peak: 250 mA Avg: 75 mA IPM⁴: 48 mA	NSC³: 65 mA Peak: 250 mA Avg: 75 mA IPM⁴: 45 mA	NSC³: 70 mA Peak: 250 mA Avg: 80 mA IPM⁴: 55 mA
Device Input and Output	Input: Tri-color LED, Buzzer, Hold @ Active Low Output: Tamper Relay 0–60 V DC @ 100 mA Max (Dry Contact)
Operating Temperature & Humidity	−31 °F to +150 °F (−35 °C to +66 °C) 0% to 95% non-condensing
Ingress Protection	IP65
Secure Element	EAL4+ certified hardware secure element
Certifications	FCC Part 15 · IC · CE · UL 294 · SIA OSDP v2 Verified · Apple ECP Licensed

¹ Read range varies based on credential type, card construction, and environmental conditions. Stated ranges are typical values measured under controlled conditions with ISO 14443A single-technology cards and HID Proximity cards.

² Current draw measured at 12 V DC nominal input. Values vary with active credential technologies and LED/buzzer state.

³ NSC = Normal Secure Channel (OSDP secure channel active, all credential technologies enabled).

⁴ IPM = Intelligent Power Management (reduced polling rate, BLE advertising interval extended).

Ordering Information

Part Number	Description	Termination
OS-SEN-S100-P	Sentinel S100 Compact NFC Reader	Pigtail
OS-SEN-S100-T	Sentinel S100 Compact NFC Reader	Terminal block
OS-SEN-S100K-P	Sentinel S100K Compact NFC Reader with Keypad	Pigtail
OS-SEN-S100K-T	Sentinel S100K Compact NFC Reader with Keypad	Terminal block
OS-SEN-S200-P	Sentinel S200 Multi-Technology Reader	Pigtail
OS-SEN-S200-T	Sentinel S200 Multi-Technology Reader	Terminal block
OS-SEN-S200K-P	Sentinel S200K Multi-Technology Reader with Keypad	Pigtail
OS-SEN-S200K-T	Sentinel S200K Multi-Technology Reader with Keypad	Terminal block

9633 Duffer Way, Gaithersburg, MD 20886 · (240) 807-9130 · sales@offsetsecurities.com

offsetsecurities.com · OS-DS-SEN-0826 Rev 2.1

Apple, Apple Wallet, iPhone, and Apple Watch are trademarks of Apple Inc. MIFARE and DESFire are trademarks of NXP Semiconductors. All other trademarks are the property of their respective owners. Specifications subject to change without notice.