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7.16
Telemetry
Telemetry is an automated communications process by which measurements are made and
other data collected at remote or inaccessible points and transmitted to receiving equipment for
monitoring. The word is derived from Greek roots: tele = remote, and metron = measure. Systems
that need external instructions and data to operate require the counterpart of telemetry,
telecommand.
Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio,
ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a
telephone or computer network, optical link or other wired communications like phase line
carriers. Many mo dern telemetry systems take advantage of the low cost and ubiquity of GSM
networks by using SMS to receive and transmit telemetry data.
7.17
TCM
A Transmission Control Unit or TCU is an Electronic Control Module (see 7.4) that controls
modern electronic automatic transmissions. A TCU generally uses sensors from the vehicle as
well as data provided by the engine control unit (ECU) to calculate how and when to change gears
in the vehicle for optimum performance, fuel economy and shift quality.
Electronic automatic transmissions have been shifting from purely hydro mechanical controls to
electronic controls since the late 1980s. Since then, development has been iterative and today
designs exist from several stages of electronic automatic transmission control development.
Transmission solenoids are a key component to these control units.
The evolution of the modern automatic transmission and the integration of electronic controls
have allowed great progress in recent years. The modern automatic transmission is now able to
achieve better fuel economy, reduced engine emissions, greater shift system reliability, improved
shift feel, improved shift speed and improved vehicle handling. The immense range of
programmability offered by a TCU allows the modern automatic transmission to be used with
appropriate transmission characteristics for each application.
IIC Journal of Innovation
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