The zone exclusion key transmitter is a device designed by Tecnologie Meccaniche according to the technical specification RFI TCSSTB SF IS 07 753.
It is a safety device used to remotely manage the exclusion of a zone from the railroad. Zone exclusion is a procedure whereby from a certain moment on that section of track no trains will pass until the zone is “restored”. This ensures that maintenance work on the line can be carried out in complete safety for workers.
To exclude a zone it is necessary to extract a key after receiving a remote consent from the Central Operations Manager (DCO), the TM key transmitter sends the exclusion request and releases the key once it has received the remote consent, only at this moment the key can be extracted excluding the zone to which it is associated. When the key is reinserted, the zone will be reinstated and train passage can resume.
The FS key transmitter remotely transmits the request for permission to remove an FS key; once the key is removed, it will be used to enable manual operation of a faulty turnout.