DAMSL™ - Dictionary and Message Specification Language

Why is tactical data link integration expensive?

In most systems tactical data link implementation is embedded in the application source code. Given the complexity of data links such as Link 11 (TADIL A & TADIL B) or JTIDS Link 16 (TADIL J) it is a very resource consuming (and therefore expensive) task to encode the message format and associated rules using a high level programming language such as C, C++ or Ada. Given the fact that each data link is unique, this task often has to be repeated for each data link implemented in the system (e.g. Link 1, Link 4, Link 11, Link 16, Link 22).

Since the data link format is embedded in the source code, each time a single field is modified in the data link standard, it is therefore necessary to carry out the design reviews, source code modification and re-compilation, regression testing and update of the associated documentation.

How can we reduce these costs?

Working from this evidence, Aerosystems has developed the Dictionary and Message Specification Language (DAMSL™). This data link processing tool provides the means to define data links (message format and transmit/receive rules) in a format that can be directly interpreted by the machine. DAMSL™ incorporates three packages: A database comprising: Message definition, Transmit/receive rules, data link implementation, Structure of the application tables. A database editor (DBED) to enter data in the database. A run-time library providing the following functions: Automatic data link processing, format conversion, interface with the application software.

DAMSL™ provides the encapsulation of the complete data link definition. In a DAMSL™ based application, the application software concentrates on processing operational information, and is independent from the format of the transmitted/received data link messages and rules. Using DAMSL™ provides a high level of flexibility. No data link messages need to be hard coded in a message structure file. Data is entered in a database via a mouse driven graphical interface. DAMSL™ enables the modification of message characteristics and/or the creation of new messages, in most cases, without having to modify the source code or recompiling the application. DAMSL™ technology is currently used in the …. · AeI Generic Integration Link Environment (AGILE). · TADIL Remote Translator (TRT). · Network Control and Initialisation Data Preparation Facility (NCIDPF). · JTIDS Situation Awareness Facility (JSAF).

JSAF - JTIDS Situation Awareness Facility

The JSAF is a PC based tactical data link monitoring and recording system developed for the UK Ministry of Defence (MoD). The JSAF is used to actively monitor (either via 1553 or direct via the terminal’s support port), and show to the operator on a graphical interface, the information exchanged between a JTIDS terminal and a host system. The system is being used operationally on E-3 and Tanker aircraft, and within a number of mobile ground stations.

JSAF features include:

• Situation awareness of the Air, Surface, Subsurface, EW information received from the terminal/host including:
  • · Worldwide mapping.
  • Use of symbols to differentiate the object types (aircraft, ship, CRC, etc).
  • Use of colours to indicate the identity (green for friend, yellow for unknown or suspect, red for hostile, white for participating units).
  • Presentation of track relevant (TN, IFF/SIF, altitude, etc) information in a configurable track tote on the graphical display.
  • Track history.
• Complete Link 16 (TADIL J) message catalogue.
• Map manipulation functions (zoom, change center, display map/outlined map, etc).
• Message display: all messages received from the terminal/host are listed in a separate window. By clicking on one or many of the messages the operator can access the detail of the message(s) in a separate window. Automatic update of the information presented in the message display window is available.
• Track hook: by specifying the TN or by picking an object on the graphical display.
• Extensive filtering capabilities (by object categories, message type, map data, etc).
• Recording of all messages received from the interface,
• Extensive analysis tools including:
  • replay at variable speed,
  • replay control (start, stop, pause, rewind, forward, change speed, etc), · replay filters (by category, identity, message type or any combination of these),
• GPS interface: provides accurate information regarding current time and position.

DLGS - Data Link Ground Station

The DLGS provides test facilities which support all facets of Link 11 (TADIL A & TADIL B) testing from LRU validation to full system checkout, during development and in service. The DLGS can be provided in build standards from light commercial up to full Military Specification. Features of the DLGS include :

• Link 11 net quality and signal characteristics analysis. Real time generation, transmission and reception of Link 11 data. The data is presented on a tactical display and in Link 11 ‘M’ series message form. Pre-scripted scenario generation and run-time interaction. Recording of received and transmitted data on all interfaces. Analysis of received and transmitted data for compliance with STANAG 5511 and host specific Implementation Plans. Simulation of host computer systems to enable end to end checking of data link functionality. Easily synchronised with other stimulus equipment to enable fully integrated system testing.

AGILE - AeI GENERIC INTEGRATION LINK ENVIRONMENT

AGILE is an innovative software kernel that can be configured to meet a wide range of tactical data link operational, simulation, training and test needs. AGILE's multi link capability supports Link 4 (TADIL C), Link 11 (TADIL A and TADIL B), JTIDS Link 16 (TADIL J) and others. AGILE will be extended to provide the capability for Link 22, VMF and other emerging standards. AGILE interfaces through a wide variety of interfaces (1553B, ARINC 429, Panavia, ATDS, NTDS) to a wide selection of terminals (Class 2, SHAR, MIDS, DTS).

The AGILE can be configured to act as either the host computer or the terminal/communication equipment. It can actively monitor transparently between a host and its co-operating data link equipment. The AGILE has applications outside testing and simulation and operator training, and could be deployed as part of a mobile ground station in support of forward and unprepared operating locations. All AGILE operations, including object simulation and message generation, are carried out in real-time and, although the capability is provided for the more technical tests and evaluations, the AGILE is capable of being operated by personnel not fully familiar with the composition and management of tactical data links. Such flexibility of operations was a primary criterion in the design of the AGILE and has been achieved by making maximum use of the latest MMI and display technologies. Using the proprietary database management DAMSL™ , supplied with the AGILE, the operator is able to create and modify either the bespoke data link database(s) or create unique database(s) for use in the operators own environment. Two major features of the AGILE rarely found in other data link exercisers are automated message interaction between simulated units and automatic message transaction processing.

The AGILE can generate the messages resulting from the interaction of simulated units either with other simulated units or the exterior system under test. This capability includes actions such as correlation, de-correlation and control together with optional modules providing specific interaction such as grid locking, relative navigation and electronic counter measures. Through the use of the flexible database management system, the AGILE user can specify the actions to be carried out when information is transacted on a message by message basis. This capability includes initiating command and control events as well as handling receipt compliance and automatic message acknowledgement.

SIM TOOLS

SIM Tools has been created by AeI to aid in the development, integration and testing of products. AeI has created a number of 'basic' tools capable of scripting MIL-STD-1553B operations for non-dynamic, repeatable low-level tests. SIM Tools make extensive use of AeI's DAMSL™ database driven messaging technology to provide comprehensive coverage of wide ranging message standards and facilitating rapid message format modification whilst the system under test is still in it's prototype/development phases.

It is the tools' high degree of independence from message standards that allow its use in development/integration activities without the need for major software development effort. The tools make use of three databases: one containing JTIDS Link 16 (TADIL J) terminal input/output and global memory status definitions, one with the Data Processor messages and one with Link 16 messages. These databases would be used to control the information scripted and transmitted by the simulation tools.

The tools operate in three modes: test definition, test execution and test review. In test definition the operator can create a series of timed events that will be 'played out' to the system under test. For MIL-STD-1553B terminal operations four types of events can be scripted: bus events, terminal output events, status data events and Link 16 message events.

Bus events allow the operator to inhibit one or either of the MIL-STD-1553B buses to check that the system under test correctly switches to alternate bus operation on a bus failure. Terminal output events allow the operator to modify the information provided in response to a poll of any of the terminal's sub-addresses. This information can be scripted bit-by-bit, or be used in conjunction with the Link 16 message events.

Status data events can be used to simulate conditions such as BIT failure within the terminal, and are normally co-ordinated with appropriate terminal output events to correctly reflect changes to a terminal's operating parameter. Link 16 message events provide easy production of Link 16-message traffic. The event data is translated into TOM events for use in the test script.

During test execution, the tool will 'play' the previously prepared script to the system under test. Whilst the test is being executed, limited information is displayed to the operator so as to minimise the impact of display refreshing on the smooth execution of the test, and to facilitate operation of the tool on 'low' spec machines. Whilst the test is being executed, all transmitted and received bus traffic is recorded for later analysis.

Test review mode allows the operator to load a recording from a previous test execution session. The recording can be reviewed on a step-by-step basis, can be used as the basis for a script and modified through test definition mode.