1, the battery is dead. Loose lines lead to abnormal power supply, or equipment is installed on abnormal circuits in the car. When the car is stationary or parked for a long time, the abnormal circuit in the car will be cut off to save electricity.

2. The equipment is in a signal blind area. Check the status of equipment on the monitoring platform. If the signal shows a downward trend or it is difficult to support communication due to poor signal, it is judged whether it is offline due to signal problems.