Background

Packet 44 applications use data transmission facilities included within European Train Control System (ETCS) for functions other than those required by ETCS.

The use of packet 44 applications has increased in GB in recent years. The applications are used to support range of functions such as Selective Door Opening (SDO), Correct Side Door Enable (CSDE), Automatic Power Change Over (APCO), Automatic Train Operation (ATO) and Automatic train Supervision (ATS). 

Management of Packet 44 applications

The requirements for managing packet 44 applications as provided in RIS-0784-CCS help prevent proliferation of bespoke applications that provide the same functionality and result in repeating the installation and transmission of the same data.

RIS-0784-CCS defines a variable NID_UKSYS as part of the GB packet 44 data structure. This can be used to identify specific packet 44 applications and support their management. 

The following table lists the values allocated to NID_UKSYS, with links to the documents that set out packet 44 protocol (packet structure and variables) and implementation rules.

NID_UKSYS value

Packet 44 function

1

TASS Management data

2

TASS Tilt Authority data

3

TASS Speed Supervision data

4-5

Not used

6

TASS Selective Door Operation (SDO) data

7

Automatic Train Supervision (ATS) data

8

Change of Traction System

9

FASDO / CSDE Door Control

10

Automatic Train Operation (ATO) data

11

Train speed units override

12

Automatic Power Change-Over, sub-packet that repeats packet 39

13

Automatic Power Change-Over, sub-packet that provides specific qualifiers

14

Automatic Control of Tractive Effort at Neutral Sections

15

Assisted Braking and Door Opening

16

(F)ASDO/CSDE Door Control