BS ISO 14827-2:2005

DATEX-ASN allows different systems to exchange relevant data. This is contained in end-application messages. Each end-application message is defined as either a “subscription” or a “publication” according to the format as specified in ISO 14827-1. DATEX-ASN defines how these end-application messages are packaged to form a complete data packet and also defines the rules and procedures for exchanging these data packets. Systems using DATEX-ASN are free to implement additional end-application functionalities according to the user requirements.

A DATEX-ASN network comprises a certain number of systems, an example of which is provided in Figure 1.

Figure 1 An example of a DATEX-ASN network

Key

Each system can be viewed as consisting of the interfaces, as shown in Figure 2:

Figure 2 System interfaces

Key

This part of ISO 14827 deals only with the communications interface. It has been designed to meet the unique requirements of TICS; however, it has been designed in a generic fashion and thus could be used for other data exchanges as well.

Systems implementing this part of 14827 sometimes operate simultaneously as a client and server, using multiple sessions. The communications cloud between the two systems may be complex or simple.