The station coding equipment is an important part of the signal system equipment, which is crucial to enforce the in-station operation safety and promote the development of the signal system.

 

However, the station coding equipment has always been the weak point of the whole system. The main problem is that it cannot be effectively detected whether the cab signal information has really been sent to the track (the present detection alarming circuits only check whether the transmitting equipment works well, instead of the running conditions of the whole system).

 

As the train speed keeps rising, it becomes imperative to equip the subjective cab signal system, which brings a higher requirement to the security and reliability of the ground transmitting equipment. The ground equipment must be able to realize the closed-loop detection of the transmitted information, i.e. be able to confirm instantly whether the cab signal information has been sent to the track. If not, the system will immediately response and send an equipment-fault alarm.

 

In ZPW2000 (including UM series) auto-blocking sections, when the train needs to switch the line (e.g. switch from up line to down line, or from down line to up line), the driver has to operate the switch to shift the cab signal frequency. However, this operation is not so easy; once some operating error occurs, the security of the train operation may be seriously threatened. Therefore, realizing the auto-shift of the cab signal frequency is quite necessary.

 

The station closed-loop coding equipment and cab signal frequency auto-shift system are just designed for the realization of the above functions.