TD503 Double-Door Anti-Tailgating Speed Gate
Secure Pedestrian Access for High-Security Entrances
For many access control projects, verifying an ID card, QR code, or face is only the first step.
A common security problem still remains: tailgating.An authorized person may open a standard pedestrian gate, while another person follows closely behind without completing their own authentication. For office buildings, data centers, factories, laboratories, financial facilities, and other restricted areas, this can create a serious access control risk.
The TD503 Double-Door Anti-Tailgating Speed Gate is designed to provide a higher level of pedestrian entrance control.Instead of using only one gate, the TD503 uses an interlocking A/B double-door structure combined with 24 pairs of infrared sensors to create a controlled passage area. The system monitors the person inside the passage and helps ensure that unauthorized followers do not enter together with an authorized user.



How the A/B Interlocking Gate Works
The TD503 uses two interlocked gates: Gate A and Gate B.
Under normal operation:
- When Gate A is open, Gate B cannot open.
- When Gate B is open, Gate A cannot open.
- The second gate opens only after the system confirms that the passage conditions are satisfied.
- In emergency situations such as a fire alarm or power failure, both gates can be released for evacuation.
Typical Entry Process
After the user is successfully authenticated:
- Gate A opens.
- The authorized user enters the middle detection area.
- The infrared sensor array checks whether another person is following.
- If no tailgating is detected, Gate A closes.
- Gate B opens and allows the authorized person to pass.
- Gate B closes after passage.
If another person follows into the detection area, the system keeps Gate A open and gives a voice warning asking the follower to leave the passage.After the system confirms that there is no unauthorized follower, Gate B can open and complete the passage process.This interlocking logic makes the TD503 particularly suitable for entrances where identity verification alone is not enough and actual pedestrian movement also needs to be controlled.
24-Pair Infrared Anti-Tailgating Detection
One of the key features of the TD503 is its 24-pair infrared sensor array.
The sensors continuously monitor the pedestrian passage area and work together with the anti-tailgating tracking control logic.Only authorized personnel are allowed to complete the passage.When unauthorized entry or abnormal following is detected, the gate can provide an audible warning and prevent the normal passage sequence from continuing.The infrared system is designed to operate reliably in different environmental conditions, including sunny and rainy conditions, while reducing false alarms.
Multiple Safety Protections
Pedestrian safety is an important consideration in entrance control projects.
The TD503 integrates several protection mechanisms.
Infrared Anti-Pinch Protection
When the gate is closing, infrared sensors monitor the passage. If an obstruction is detected, the system provides an alarm and prevents unsafe closing.
Obstacle Rebound
If the gate wing encounters an obstacle during closing, the motor automatically stops and the gate can return to the open position.
This helps reduce the risk of injury to pedestrians.
Brake Lock Anti-Impact Protection
If someone attempts to force through the gate without an opening signal, the high-precision clutch and brake mechanism reacts after the swing arm is displaced by a preset angle.
The system can then lock, alarm, and automatically reset.This design helps protect both pedestrians and the internal gate mechanism while reducing mechanical damage caused by repeated impacts.
Brushless DC Drive for Long-Term Operation
The TD503 uses a brushless DC gate mechanism.
The system performs a self-check after power-on and is designed for a low failure rate and long service life.
For commercial buildings, industrial sites, office facilities, and other projects where pedestrian gates operate frequently every day, a reliable drive mechanism can reduce maintenance requirements and long-term operating costs.
Flexible Access Modes for Different Traffic Conditions
Not every entrance has the same pedestrian flow.
The TD503 therefore supports multiple access configurations, including:
- A/B double-door operation
- Gate A only
- Gate B only
- Normally open mode
- Single-door anti-tailgating mode
These modes can be switched according to project requirements and pedestrian traffic conditions.
The system can also support:
- Controlled access in both directions
- Controlled entry with sensor-based exit
- Adjustable opening and closing speed
During peak periods, the operating mode can be changed to improve pedestrian flow and reduce congestion.
Passage Memory for Faster Continuous Access
For entrances with multiple authorized users arriving continuously, the TD503 includes a passage memory function.When several pedestrians authenticate in sequence, the system can remember the number of authorized passages and close the gate after all authorized users have completed their passage.This allows the system to maintain security while improving throughput during busy periods.
The specified passage rate is approximately 20–60 persons per minute, depending on pedestrian conditions and the selected operating mode.
Automatic Reset and Abnormal Passage Handling
If a user successfully authenticates but does not pass within the specified time, the system automatically cancels that access authorization.
The passage time can be configured according to project requirements.If a person remains inside the middle detection area for an extended period, the system can periodically reopen Gate A and provide a prompt to leave the passage.For special situations such as visitors, children above 90 cm in height, or oversized luggage, manual assistance or a dedicated access procedure may be required if the infrared system detects multiple persons.
Fire Alarm and Emergency Release
For emergency evacuation requirements, the TD503 supports a fire alarm interface.When a fire signal is triggered, the gate automatically opens to allow people to evacuate quickly.In the event of a power failure, the gate wings also automatically open, allowing free pedestrian passage and helping prevent crowd panic.
LED Indicators and Voice Prompts
Integrated LED indicators display the current passage direction and gate status.
Different visual and audible prompts can be provided for:
- Authorized access
- Unauthorized entry
- Abnormal passage
- Tailgating
- Other operating conditions
The system also supports customizable voice prompts, allowing different projects to configure specific messages after card authentication or other access events.
Designed for Indoor and Outdoor Installation
The TD503 enclosure is manufactured from 1.5 mm national-standard 304 stainless steel, providing a strong and stable structure.
A grooving manufacturing process helps reduce visible gaps and provides a cleaner appearance.The enclosure also adopts an outdoor waterproof structural design, allowing the gate to be used in both indoor and outdoor environments.The inward-folding top cover makes it easier to install face recognition or other access control terminals close to a wall.For coastal areas, chemical plants, or other highly corrosive environments, 316 stainless steel is recommended according to the project environment.
Easy Installation and Maintenance
The gate wing uses a clamp-style mounting design, making replacement and maintenance more convenient.The brushless controller uses a simplified master-slave architecture. Only a 4-core connection cable is required between the main and secondary units, helping simplify on-site wiring and future maintenance.The machine also includes a leakage protection device.The operating voltage of the relevant internal electrical modules does not exceed 24V, providing additional protection during installation and maintenance.
Technical Specifications
| Item | Specification |
|---|
| Model | TD503 |
| Product Type | A/B Double-Door Anti-Tailgating Speed Gate |
| Dimensions | 2500 × 120 × 1000 mm |
| Mechanism Projection | 75 mm |
| Passage Width | 550–900 mm |
| Cabinet Material | 1.5 mm 304 Stainless Steel |
| Gate Wing Material | Acrylic |
| Drive Type | Brushless DC Mechanism |
| Infrared Sensors | 24 Pairs |
| Communication / Interfaces | RS485, Left Open, Right Open, Fire Alarm Interface |
| Passage Speed | Approx. 20–60 Persons/Minute |
| Power Supply | AC 220V, 50/60Hz |
| Power Consumption | ≤180W per lane |
| Standby Power | <18W |
| Operating Temperature | -20°C to 70°C |
| Relative Humidity | ≤95%, Non-condensing
|
Typical Applications
The TD503 is suitable for projects where pedestrian identity and actual passage behavior both need to be controlled.
Typical applications include:
- Corporate headquarters
- Office buildings
- Data centers
- R&D laboratories
- Industrial factories
- Financial institutions
- Government facilities
- Restricted production areas
- High-security office zones
- Controlled entrances requiring anti-tailgating protection
It can also be integrated with different third-party access control devices according to the project architecture.
The TD503 combines A/B gate interlocking, 24-pair infrared detection, anti-tailgating control, multiple safety protections, emergency release, and flexible operating modes to provide more controlled pedestrian access.
For system integrators, security contractors, distributors, and project developers, the TD503 can be used as part of a complete pedestrian access control solution for projects requiring a higher level of entrance security.
XIBING provides pedestrian access control equipment and customized solutions for global B2B projects.



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