Transponder is a kind of transmission equipment that can send message information to vehicle subsystem, which can not only transmit fixed information, but also connect with roadside units to transmit variable information.
The transponder equipment sends the following information to the train control vehicle-mounted equipment:
(1) Basic parameters of the line: such as line gradient, track section and other parameters;
(2) Line speed information: such as the maximum allowable speed of the line and the maximum allowable speed of the train;
(3) Temporary speed limit information: when the running speed of the train is limited due to construction and other reasons, temporary speed limit information is provided to the train;
(4) Station route information: According to the route of vehicles received and sent by the station, provide the train with parameters such as "line slope", "line speed" and "track section";
(5) Switch information: give the lateral allowable train speed of the front switch;
(6) Special positioning information: such as bow lifting, entering and leaving the tunnel, whistling, train positioning, etc.
(7) Other information: fixed obstacle information, train running target data, link data, etc.
Passive transponder (group) is used to send fixed data and provide fixed parameters of the line, such as line gradient, line allowable speed, track circuit parameters, link information, train control level switching, etc.
Active transponder: sends variable information. It must be connected with the LEU equipment through a special transponder cable, and the transponder message information can be changed according to the message sent by the LEU equipment and transmitted to the train. It is connected with LEU (Ground Electronic Unit) and used to send information from LEU. In the speed-up section of the existing line, an active transponder is arranged at the entrance and exit section of the station, which mainly sends route information and temporary speed limit information.
Whether passive transponder or active transponder, its working principle is the same. When the train passes above the ground transponder, after the transponder receives the electromagnetic energy from the point information receiving antenna of the train-controlled on-board equipment, the transponder converts this energy into working power, starts the electronic circuit to work, and circularly sends the pre-stored or LEU-sent 1023 transponder transmission message until the electromagnetic energy disappears.
Each transponder (group) has a number, which is unique within the scope of the national railway.
Passive transponders (also called fixed transponders) are installed at the entrance of the block area and the entrance and exit of the station, and are used to transmit information such as the length of the block area, line speed, line slope, train positioning and so on. Train control vehicle-mounted equipment. Active transponders (also called variable transponders) are installed at the entrance and exit ends of the station. When the train passes through the transponder, the transponder provides the train with information such as receiving route parameters and temporary speed limit.
The transponder device can be simply understood as a data memory and a transmitter. When the vehicle antenna activates the transceiver, the transceiver transmits its own stored transceiver information or the transceiver information transmitted by the ground electronic unit (LEU).