Train Activation
Overview
In IT terms, an activation message is produced when a 'train entity' is created from a 'schedule entity'. The train entity refers to a single run of a train, starting on one day whereas the schedule entity is potentially valid for several months at a time. Within TRUST, this process is known as 'Train Call'
For most trains, there is no corresponding business event which triggers an activation, which happens automatically (auto-call) before the train is due to run.
The exception to this is for schedules which are "Runs as required", or "Runs to terminals/yards as required" - flagged with Q or Y in the schedule. By default, it is assumed that the train will not run unless the train operator decides that it will, and submits a message to the TRUST system. This will then cause the schedule to be activated for that day, and the activation process is known as 'manual call'.
Train activations are usually received either one or two hours before the train is due to run, but these trains may be manually called earlier if some details of the train are due to change.
The activation message includes the schedule UID, schedule STP Indicator, and a 10-character ID (unique only within a calendar month) which is seen in all further message for a the train.
Data structure
Header
| Field | Description |
|---|---|
| msg_type | Set to '0001' for an activation message |
| source_dev_id | Always blank for an activation message |
| source_system_id | Set to "TRUST" for an activation message |
| original_data_source | Set to "TSIA" for an activation message |
Body
| Field | Description |
|---|---|
| train_id | Set to the 10-character unique identity for this train, and will appear in other TRUST message types |
| creation_timestamp | The time, in milliseconds, when the train was originally created in TRUST |
| tp_origin_timestamp | The date, in YYYY-MM-DD format, the train runs. For trains activated before midnight that run after midnight, this date will be tomorrow's date - see the note below |
| train_uid | The UID of the schedule being activated - either a letter and five numbers, or a space and five numbers for VSTP trains |
| sched_origin_stanox | STANOX of the originating location in the schedule. |
| schedule_start_date | The start date of the schedule |
| schedule_end_date | The end date of the schedule |
| schedule_source | Set to 'C' for schedules from CIF/ITPS, or 'V' for schedules from VSTP/TOPS |
| schedule_type | Either C (Cancellation), N (New STP), O (STP Overlay) or P (WTT/LTP) |
| schedule_wtt_id | The headcode and TSPEED of the train (either '1', '2', '3', '4', 'C', 'M', 'N' or 'O') |
| d1266_record_number | Either '00000' for a CIF/ITPS schedule, or the TOPS unique ID of the schedule |
| tp_origin_stanox | If the train is due to start from a location other than the origin (i.e. it is part-cancelled), the STANOX of the location at which the train starts, otherwise the STANOX of the scheduled origin location. If this field is populated, it will be typically be in response to a VAR issued through VSTP or SCHEDULE. |
| origin_dep_timestamp | The estimated WTT time of departure from the originating location |
| train_call_type | Either 'AUTOMATIC' for auto-called trains, or 'MANUAL' for manual-called trains |
| train_call_mode | Set to 'NORMAL' for a train called normally, or 'OVERNIGHT' if the train is called as part of an overnight batch process to activate peak period trains early |
| toc_id | Operating company ID as per TOC Codes |
| train_service_code | Train service code as per schedule |
| train_file_address | The TOPS train file address, if applicable |
About the tp_origin_timestamp field
There is currently a problem with the 'tp_origin_timestamp' field due to the truncation of the timestamp. This problem only occurs during daylight savings, and only for trains which start their journey between 0001 and 0200 the next day.
To work around this problem, use the date in the 'origin_dep_timestamp ' field.