Train Movements: Difference between revisions

Revision as of 10:01, 1 August 2012

Overview

The train movements feed contains messages produced by TRUST. These messages are one of eight types, all in JSON format:

Lifecycle

Before any action can be taken on a train, the schedule must be activated. An Activation message will be received, which will link a schedule to a 10-character train identity. This identity is referenced in all other message types, and there is no need to calculate it manually.

A train may be cancelled (either entirely or from a particular calling point onwards) through a Train Cancellation message, or start from a location other than the originating location through a [Change of Origin] message. A train may be reinstated after cancellation through a Train Reinstatement message.

One point to note - the Change of Identity message type is rarely seen. This is used when a train running under one class (e.g. a Class 4 freight with a train identity starting 4---) must run under a different class for some reason - usually because it must run at a lower speed due to the type of load it is carrying.

Data Format

Individual STOMP Packets, can contain between 1 and 32 JSON encoded strings. Each representing a single Train Movement Entry.

Each JSON packet can contain any number of the following columns (depending on available data and message type). Each packet consists of a Header and a Body.

- All Timestamp columns are in Milliseconds

Header

msg_type as above
source_dev_id
user_id - for when a message is not added Automatically this represents who initiated the message
original_data_source - known values
- SDR
- SMART
- TOPS
- TRUST DA
- TSIA
msg_queue_timestamp,
source_system_id, normally TRUST

Body

train_id
event_type, is the Train Arriving or Departing, blank for Activation/other messages that are not 0003
- ARRIVAL
- DEPARTURE
gbtt_timestamp
original_loc_stanox
planned_timestamp, the timestamp the event is supposed to occur
timestamp_variation, number of minutes between actual time and reporting time, (always positive, refer to variation_status for early/late)
original_loc_timestamp,
current_train_id, used when the the msg_type is 0007, used to link between the old and new train_id
delay_monitoring_point
next_report_run_time
reporting_stanox, the place reporting the update, but STANOX code,
actual_timestamp, the timestamp the event occurred
correction_ind
event_source,
- AUTOMATIC
- MANUAL
train_file_address
platform, the platform the train is using, (not always populated)
division_code
train_terminated, has the train completed this run meaning the end of the train running under its current train_id, it then deactivates
offroute_ind, is the train running off schedule
variation_status, qualifier for timestamp_variation
- EARLY
- LATE
- OFF ROUTE
- ON TIME
train_service_code, the schedule reference index
toc_id
loc_stanox, the Stanox/location of the train
auto_expected
direction_ind,
- UP
- DOWN
route
planned_event_type, the kind of event that was expected
- ARRIVAL, the train arrived somewhere
- DEPARTURE, the train left somewhere
- DESTINATION, the train has reached the end of the line, All Change
next_report_stanox, STANOX of the next expecte reporting location
line_ind

@@ Line 18: / Line 18: @@
 A train may be cancelled (either entirely or from a particular calling point onwards) through a [[Train Cancellation]] message, or start from a location other than the originating location through a [Change of Origin] message.  A train may be reinstated after cancellation through a [[Train Reinstatement]] message.
-One point to note - the [Change of Identity] message type is rarely seen.  This is used when a train running under one class (e.g. a Class 4 freight with a train identity starting 4---) must run under a different class for some reason - usually because it must run at a lower speed due to the type of load it is carrying.
+One point to note - the [[Change of Identity]] message type is rarely seen.  This is used when a train running under one class (e.g. a Class 4 freight with a train identity starting 4---) must run under a different class for some reason - usually because it must run at a lower speed due to the type of load it is carrying.
 == Data Format ==