For commercial vehicles such as trucks, tractors, and trailers, frequently changing trailers or cargo bodies is a common operating scenario. A tractor may need to work with different trailers, and each trailer may be equipped with its own rearview camera.
Traditional wired vehicle camera systems typically use video cables to connect the camera on the trailer to the monitor inside the cab. When vehicles frequently change trailers, restoring the camera connection quickly becomes a practical challenge. If the video cable needs to be reconnected or rearranged every time the trailer is changed, it not only adds extra steps but can also reduce vehicle operating efficiency.
PLC wireless transmission technology provides a different approach. By adding a transmitter (TX) and receiver (RX) between the camera and monitor, the camera and monitor can retain their wired connections while the video transmission between the TX and RX is converted to wireless. More importantly, the TX and RX can automatically pair through the vehicle's power lines.
What Challenges Do Vehicle Camera Systems Face When Trailers Are Frequently Changed?
For transport vehicles that frequently switch trailers or cargo bodies, the camera systems not only need to transmit video stably but also must be able to adapt to constantly changing vehicle combinations.
1. Re-establishing the Camera Connection After Every Trailer Change
Suppose one tractor needs to work with several different trailers. The camera is normally installed at the rear of the trailer, while the monitor is located inside the tractor cab. In a traditional wired system, a video connection needs to be established between the tractor and trailer. When the trailer is changed, the connection between the camera and monitor needs to be handled again.
For vehicles that only change trailers occasionally, this may not be a major issue. However, for transport vehicles that switch trailers several times a day, repeatedly performing the same connection process can become increasingly inconvenient.
2. Long Video Cables Increase the Complexity of Vehicle-to-Vehicle Connections
Traditional wired camera systems transmit the camera signal to the monitor through video cables. For longer vehicle combinations, these cables need to cover a considerable distance and must be routed, secured, and protected along the vehicle structure.
When the tractor and trailer are frequently separated and reconnected, the video cable connection between the two vehicles also needs to be handled repeatedly, adding complexity to daily operations.
3. Rapid identification and connection of the correct camera among multiple trailers.
When one tractor works with multiple trailers throughout the day, the situation becomes more complicated if several trailers are parked nearby and each trailer is equipped with its own camera. Every time the tractor switches trailers, the system needs to ensure that it connects to the correct camera.
Ideally, once the new trailer is connected and powered on, the system should automatically establish the connection and display the corresponding camera feed—without requiring manual pairing, troubleshooting, or checking the screen to confirm whether the correct camera has been connected.
What Is PLC?
PLC stands for Power Line Communication. As the name suggests, it is a communication technology that uses existing power lines to transmit communication signals.
In this system, the camera is connected to the TX, the monitor is connected to the RX, while the TX transmits the video signal wirelessly to the RX. At the same time, the TX and RX can establish pairing automatically through the vehicle's power lines.
The overall signal path can therefore be understood as:
Wired Camera → TX → Wireless Video Transmission → RX → Monitor
This architecture retains the existing wired connections at the camera and monitor ends while replacing the long-distance video cable between them with wireless transmission. As a result, the vehicle camera system can offer greater installation and operational flexibility.
How Does PLC Work?
To understand how PLC converts a wired vehicle camera system into wireless transmission, the entire system can be divided into three sections:
Camera Side → Wireless Transmission Side → Monitor Side
1. Connect the Wired Camera to the TX
First, the camera is connected to the TX transmitter using a video cable.
The camera continues to use a conventional wired connection, so there is no need to change how the camera itself operates. The TX receives the camera's video signal and prepares it for wireless transmission.
2. Connect the TX and RX to the Vehicle Power Supply
The TX and RX are connected to the vehicle's power supply respectively.
For PLC automatic pairing to work, the two devices need to be connected to the same vehicle power wiring system, with the same battery and ground reference.
3. PLC Transmits the Pairing Signal Through the Power Line
Once the TX and RX are powered on, the PLC pairing signal is transmitted through the vehicle's power line.
This means that the vehicle's existing power wiring serves two functions: it supplies power to the devices and also acts as the PLC communication channel between the TX and RX.
4. The TX and RX Automatically Pair
Once PLC pairing is completed, the TX and RX establish a one-to-one connection.
Under normal conditions, the system takes approximately 3–20 seconds to complete automatic pairing.
5. Video Is Transmitted Wirelessly
After pairing is completed, the camera video is not transmitted through PLC.
Instead, the video signal is transmitted wirelessly between the TX and RX through their antennas.
Why Convert a Wired Camera System to Wireless Transmission?
The PLC wireless solution does not require users to replace their existing wired cameras. Instead, it changes the way video is transmitted between the camera and monitor through the TX and RX.
1. Reduce Video Cabling Between the Tractor and Trailer
In a traditional wired system, the camera and monitor need to be connected through a video cable.
After adding the TX and RX, the camera remains connected to the TX through a video cable, and the monitor remains connected to the RX through a video cable. However, the long-distance video cable between the TX and RX is no longer required.
2. Simplify Installation and Removal
Traditional video cables need to be connected, routed along the vehicle structure, secured, and protected.
With wireless video transmission, the amount of video cabling between the TX and RX can be reduced, simplifying installation and removal when vehicles are separated and reconnected.
3. Improve the Flexibility of Vehicle Camera Systems
For vehicles that frequently change trailers or cargo bodies, reducing video cable connections means there is no need to repeatedly handle long-distance video cables whenever the vehicle combination changes.
Instead, once the TX and RX are connected to the vehicle power supply, they can automatically pair and establish the connection.
How Is PLC Different from Traditional Wired and Non-PLC Wireless Systems?
Different vehicle camera systems use different approaches to video transmission and device connectivity.
1. Traditional Wired Systems
In a traditional system, the camera and monitor are directly connected through a video cable.
This approach has a simple structure. However, when the tractor and trailer need to be frequently separated and reconnected, the long video cable can increase the amount of work required for connection and removal.
2. Non-PLC Wireless Systems
Non-PLC wireless solutions rely on wireless communication and typically require manual pairing between the TX and RX using pairing buttons.
When multiple identical or similar wireless systems are operating nearby, it can be difficult to ensure that the correct TX and RX are paired with each other.
3. PLC Wireless Systems
In a PLC wireless system, the camera and monitor remain connected to the TX and RX respectively through wired connections, while the TX and RX use the vehicle's power line to automatically establish pairing.
In addition, PLC systems use FHSS (Frequency Hopping Spread Spectrum) technology, allowing wireless communication to switch between multiple frequencies according to a defined pattern. Depending on the vehicle type and wiring environment, the system can adjust its communication frequency to improve stability and compatibility.
Because vehicle power systems and wiring layouts vary between vehicle models, the types and frequencies of electrical interference may also differ.
With frequency-hopping technology, the system can switch between multiple frequencies, allowing it to better adapt to different vehicle environments and improve communication stability.
Where Can PLC Be Used?
Whether it is a multi-camera application on the same vehicle or camera switching between different trailers in the same fleet, PLC automatic pairing provides a more flexible wireless connection method for wired vehicle camera systems.
1. Fleets with Multiple Trailers
For fleets operating multiple trailers, each trailer can be equipped with an independent camera system. PLC automatic pairing helps different vehicle combinations quickly establish the corresponding connection, reducing the complexity of daily fleet operations and trailer changes.
2. Multi-Camera Applications
PLC solutions can also be applied to multi-camera systems. Multiple cameras can be installed at different positions on the same vehicle to provide comprehensive visibility and cover different viewing angles around the vehicle.
3. Upgrading Existing Wired Camera Systems
An existing wired camera system can gain wireless transmission capability simply by adding a TX and RX, without redesigning the entire camera system.
What Does PLC Bring to Vehicle Camera Systems?
For transport vehicles that frequently change trailers or cargo bodies, one of the main practical challenges of traditional wired vehicle camera systems is the need to repeatedly manage the video connection between the tractor and trailer.
The PLC wireless solution provides a more flexible approach. Instead of replacing the existing camera, a TX and RX can be added to convert the video transmission between them from wired to wireless. At the same time, the TX and RX can automatically pair through the vehicle's power line, while FHSS technology helps the system adapt to different vehicle and operating environments.
This architecture reduces the need for long-distance video cabling between the tractor and trailer, making the camera system better suited to transport applications where trailers are frequently changed.
For commercial vehicles such as trucks, trailers, and fleet vehicles, PLC wireless technology provides a practical way to convert a traditional wired camera system into wireless video transmission, allowing the vehicle camera system to adapt more flexibly to constantly changing vehicle combinations.
