====== Introduction ======
This Telemetry Attributes Transfer Standard (TMATS) Handbook is intended to
supplement Chapter 9 of RCC IRIG 106 Telemetry Standards. Practical guidance for properly
generating and using TMATS files is provided and examples of some of the more commonly
used TMATS features are given. Since there may be multiple ways of describing these features
in TMATS, the examples are intended to illustrate “best practices.” The overall purpose of this
handbook is to improve the use of TMATS as a standard by presenting clear guidelines and
thereby eliminating any misinterpretations that may exist.
The RCC IRIG 106 sets forth standards for various aspects of telemetry (TM) data
transmission, recording, and processing. These standards constitute a guide for the orderly
implementation of telemetry systems and provide the necessary criteria on which to base
equipment design and modification. Their purpose is to ensure efficient spectrum utilization,
interference-free operation, interoperability between ranges, and compatibility of range user
equipment at the ranges.
The RCC IRIG 106 is the master source of all information for TM data
transmission, recording, and processing. Therefore, the RCC IRIG 106 is
assumed to be correct if a discrepancy is found between it and this
handbook. If a discrepancy is found, it should be immediately reported to
the RCC Secretariat or to the Telemetry Group (TG). The RCC IRIG 106
can be viewed or downloaded from the RCC public web site,
http://www.wsmr.army.mil/RCCsite/Pages/default.aspx.
===== The Range Commanders Council (RCC) and History of TMATS =====
The RCC held its first meeting in August 1951. In March 1952, the RCC Commanders
established the Inter-Range Instrumentation Group (IRIG) to make recommendations for
improvement of range instrumentation and conservation of the resources of the ranges. After a
few meetings, the IRIG recognized the need to expand and specialize, and the IRIG Steering
Committee was created to oversee several IRIG technical working groups. In 1971, the IRIG
Steering Committee was disestablished, and the IRIG working groups became known as the
RCC working groups. To this day, the RCC standards documents are still commonly referred to
as "IRIG standards."
The TMATS Standard was developed jointly by the RCC Telemetry Group Data
Multiplex Committee and Data Reduction and Computer Group under a joint task begun in 1989.
The standard was first published in 1993 as Chapter 9 of RCC IRIG 106. Since 1993, the Data
Multiplex Committee has maintained this standard, with the primary goal of keeping it up to date
with data types and features currently in use. Custom software tools were developed to work
with the original “code name” TMATS format. In 2004, work began on a version of TMATS in
the more widely used XML (eXtensible Markup Language) format. The initial version of a
standard TMATS XML schema was published in 2007. Expressing TMATS in XML allows
existing off-the-shelf XML software tools to be used to work with TMATS files. Both formats
will be maintained for the foreseeable future.
The TMATS standard provides the common definition of the set of information needed to
fully describe the data being transmitted from, or recorded on, an item under test. A TMATS file
serves as the medium of exchange between the information source (usually an instrumentation
organization) and the user (usually a test range).
TMATS is not a data standard, but rather a description of existing data standards. For
example:
a. The TMATS description of pulse code modulation (PCM) data in the P-Group and
D-Group is based on the standards for PCM data in of RCC IRIG 106, Chapter 4.
b. The TMATS description of 1553 bus data in the P-Group and B-Group is based on
the standards for 1553 bus data in Military Standard 1553 (MIL-STD-1553) and RCC
IRIG 106, Chapter 8.
As these data standards are modified and standards for new data types are created,
TMATS is also changed to reflect the improvements in the data standards.
TMATS was developed to improve the process of getting the information needed to
describe the telemetry data for a particular test from its source to the system being used to
process the data. See RCC IRIG 106, Appendix H, for a description of this process.
TMATS files are usually produced and read by software. Automating this process
reduces the time needed to prepare a telemetry processing system to support a test and eliminates
errors that inevitably result from entering this information manually.
===== Telemetry =====
{{ :ch9_handbook:telemetry_system_components.gif?nolink |}}
Telemetry System Components
The American Heritage Dictionary defines telemetry as:
//"The transmission of data by radio or other means from remote sources to receiving stations for recording and analysis."//
Telemetry signals are formatted in what is commonly known as “pulse code modulation,”
or PCM. Telemetry signals containing data of interest such as heading, air speed, altitude, voice,
video, scientific information, and weather information, are transmitted from test items such as
aircraft, weapons, ships, and ground vehicles.
Components of a basic telemetry system typically include:
- Signal transducers.
- Data acquisition system.
- Transmitter.
- Receiver.
- Telemetry processing system.
- Data display system.
With these systems, telemetry data can be transmitted over a radio link for retrieval at a
ground station so that in-flight progress can be monitored.