The Dahua ASC4202B-D is a professional double-door bidirectional access controller designed for medium to large-scale access control systems. Powered by an embedded processor running Linux with built-in web configuration, it delivers reliable performance and flexible management.

Key features:

Controls 2 doors in bidirectional (in/out) mode
Supports up to 100,000 users, 100,000 cards, 100,000 passwords, 10,000 fingerprints and 500,000 access records
Multiple verification methods: card, password, fingerprint, QR code, remote unlock and multi-factor combinations
Advanced functions including anti-passback, multi-door interlock, remote verification, first-user unlock, restricted/trusted lists
Connectivity: 5 × RS-485 (4 for readers + 1 extension), 4 × Wiegand, 1 × RJ-45 (10/100 Mbps), 4 alarm inputs/outputs (expandable)
Powered by Standard PoE or 12 VDC, low power consumption (≤ 3 W)
Compact PC+ABS housing for surface or DIN-rail mounting
Compatible with Dahua SmartPSS Lite, DSS Pro and DMSS platforms

Ideal for offices, commercial buildings, residential complexes and multi-door installations requiring high capacity and advanced security features.

Parameter    Specification
SYSTEM
Model    DHI-ASC4202B-D / ASC4202B-D
Product Type    Double Door Two-way (Bidirectional) Access Controller
Main Processor    Embedded Processor
Network Protocol    IPv4; UDP; P2P; IPv6; TCP
OSDP Protocol    Yes
Interoperability    ONVIF PROFILE C
SDK / API    Yes
BASIC
Buzzer    Yes
Casing Material    PC+ABS
Unidirectional or Bidirectional    Bidirectional
FUNCTION
Verification Method    Card; Password; Fingerprint; Remote; QR Code
Period List    128 groups
Holiday Period    128 groups
Network Update    Yes
First User Unlock    Yes
Remote Verification    Yes
Restricted List / Trusted List    Yes
Peripheral Card Reader    Supports 4-channel RS-485 card readers and 4-channel Wiegand card readers
Multi-door Interlock    Yes
Multi-user Authentication    Yes
Real-time Monitoring    Yes
Multi-factor Authentication    Yes
Web Configuration    Yes
CAPACITY
User Capacity    100,000
Fingerprint Capacity    10,000
Card Capacity    100,000
Password Capacity    100,000
Record Capacity    500,000
PORTS
RS-485    5 ports (4 for card readers + 1 extension)
Wiegand    4-channel input
Network Port    1 × RJ-45 10/100 Mbps self-adaptive
Alarm Input    4 channels (expandable to 8 with external module)
Alarm Output    4 channels (expandable to 8 with external module)
Exit Button    2 channels
Door Status Detection    2 channels
Lock Control    2 channels
ALARM
Anti-pass Back    Yes
Tamper Alarm    Yes
Duress Alarm    Yes
Door Sensor Timeout    Yes
Intrusion    Yes
Illegal Card Exceeding Threshold    Yes
Duress Fingerprint    Yes
GENERAL
Power Supply    Standard PoE; 12 VDC 1A (no peripheral devices)
Power Consumption    ≤ 3 W (may increase with connected devices)
Product Dimensions (L × W × H)    210.0 mm × 106.0 mm × 34.1 mm (8.27" × 4.17" × 1.34")
Gross Weight    0.54 kg (1.19 lb)
Operating Temperature    –30 °C to +60 °C (–22 °F to +140 °F)
Operating Humidity    5%–95% (RH), non-condensing
Operating Environment    Indoor
Installation    Surface Mount; Guide Rail Mount