Project Description
Joint-less Track Circuit TCN422
Track vacancy detection is an essential requirement of any signaling system
Joint-less Track Circuit
Track vacancy detection is an essential requirement of any signaling system which could be achieved by different methods; and Track Circuit is one of them which is widely in use. The basic theory of operation of fail-safe closed loop track circuits are all the same but there are diversified responses to challenging requirements. Track circuit TCN422 is coded, joint-less and could easily be configured as the wayside interface to train ATPIATC onboard unit.
Structure:
Track circuit TCN422 consists of the following units:
- Indoor unit
- Wayside unit
Principle of Work
Key Features
- 2 out of 2 processing module
Unique code for each Track Circuit
Safe overlap on adjacent tracks
Optional Track to Train Data Transmission
- Optional data communication link with any upstream system
With up to 3 receiver sides
Cascaded if more than 3 receiver sides required
Electrically isolated from adjacent Track Circuits
Well used with relay and electronic Interlocking systems
Suitable for Track section length up to 1000m
Modular design
Indoor unit :
Each Indoor unit has 4 modules:
- 2 out of 2 processing module
- Transmitter module
- Up to 3 Receiver modules
- Output Module
The modules are slide-in cards in a 19″ rack mount housing. Each track circuit may have 1, 2 or 3 receiving sides and two or more of them are cascaded if more receiving sides are required.

Wayside unit :
This unit is installed close to the track in a robust junction box. It consists of passive components to tune electrically adjacent track circuits. The TUs (Tuning Unit) of transmitter side and receiving side are the same. The wayside units of two adjacent Track Circuits are located a few meters apart. A cable bond is shaped between two running rails in this length. This length of rail plus adjoining cable is called the tuning area. Tuning area is selectively tuned by each TU to show a short circuit at the adjacent track circuit frequency while open circuited at its own.
ATP/ATC Application
New Product :
Introducing Universal Track Circuit TUN458 with the following key features :
- Similar hardware for all frequencies
- Literally selectable track circuit frequencies
Specific fixed frequencies are generally used in track circuits. But what shall be done when according to technical reasons, without sacrificing of other features, frequencies should be literally selected?
TUN458 is the answer to the above requirement. All modules of this track circuit including its 2 out of 2 processing module are slide-in cards in a 19” rack mount housing.
The hardware of all track circuits, irrespective of the track circuit frequency, is the same. Reduction of hardware diversity means lower spare parts and lower required warehouse shelves.
Tel
+98 21 22924051
Fax
+98 21 22924055
Working Hours
8:00 am – 5:00 pm