1. On-site operation and maintenance of communication and signaling systems along the line (the most common scenario)

There are a large number of signals, switch machines, axle counting equipment and communication base stations distributed along the track. These devices are usually located outside in a control cabinet (as shown in your last picture).

Direct physical connection: Engineers use RS232/RS485, CAN bus or customized aviation plugs on the side of the tablet to directly physically connect to the PLC (programmable logic controller) or control board inside the signal cabinet.

Parameter configuration and waveform analysis: Run special diagnostic software on the tablet to read the waveform of the switch's operating current, the status feedback of the relay, etc. in real time, so as to accurately determine whether the equipment is jammed or electrically aged.

2. On-board troubleshooting of train control and diagnostic system (TCMS)

When the train returns to the depot for maintenance or when an accidental failure occurs during operation, this type of flat panel acts as a portable "stethoscope".

Bus data access: It can access the train’s internal network (such as MVB multifunctional vehicle bus or Ethernet TRDP).

Code-level diagnosis: Engineers use a train diagnostic host computer developed in C++ or C# on a tablet to read the underlying fault codes (FaultCodes), traction converter data and brake system pressure values, and can quickly troubleshoot without driving the train to a large inspection platform.

3. Track and catenary defect detection combined with machine vision

This is an important direction for the current intelligent transformation of the rail transit industry. Since this type of tablet is usually equipped with a high-performance processor, it is fully capable of processing image data at the edge.

Vision algorithm deployment: Engineers can connect it to an industrial camera and run professional machine vision software like Halcon or VisionMaster locally on the tablet.

Real-time flaw detection: When the rail car is running at low speed or the manual cart is inspected, the camera is used to take pictures of the rail surface or the overhead catenary, and the visual algorithm is used to identify cracks and scratches on the rail surface or the damage of the catenary insulator in real time, and automatically record the GPS/Beidou coordinates.

4. Ground control station for intelligent inspection unmanned systems (robots/drones)

In areas such as the bottom of high-speed railway bridges or long tunnels that are difficult for people to easily reach, rail transit systems are increasingly introducing drones or crawler inspection robots.

Collaborative control: This tablet can serve as a portable ground control station (GCS) for unmanned systems.

Data fusion: With the underlying control system developed based on ROS2 and other architectures, the tablet is not only responsible for sending path planning and waypoint instructions, but also receiving visible light,infrared temperature measurement video streams and radar point cloud data sent back by the robot through high-bandwidth microwave links in real time for preliminary rendering and decision-making on site.

5. Emergency rescue and on-site data relay

When encountering equipment failure caused by sudden bad weather (heavy rain, heavy snow), the emergency repair environment is extremely harsh.

Its wide temperature characteristics (usually can be turned on normally from -20°C to 60°C) and anti-drop design ensure that it will not shut down in mud, rain or snow.

The built-in 4G/5G module can be used as a temporary data relay node to transmit complex on-site fault data and video images back to the dispatch center in real time to assist experts in providing remote guidance.