SCHRADER ELECTRONICS SCHEB TPMS Transmitter User Manual
- June 9, 2024
- Schrader Electronics
Table of Contents
SCHRADER ELECTRONICS SCHEB TPMS Transmitter
Installation
The TPMS Transmitter is installed to the valve body in each tyre of a vehicle. The unit measures tyre pressure periodically and transmits this information by RF communication to a receiver inside the vehicle. In addition, the TPMS Transmitter performs the following functions:
- Determines a temperature compensated pressure value.
- Determines any abnormal pressure variations in the wheel.
- Monitors the state of the Transmitters’ internal battery and informs the receiver of a low battery condition.
Fig 1: Sensor block diagram
Fig 2: Schematic diagram
(Please see SCHEB Circuit Schematic File.)
Modes
Rotating Mode
While the sensor/transmitter in the Rotating Mode, it shall satisfy the
following requirements. The sensor/transmitter shall transmit an instantaneous
measured data, if a pressure change of 2.0 psi from the last transmission or
greater has occurred with respect to the following conditions. If the pressure
change was a decrease of pressure, the sensor/transmitter shall transmit
immediately every time it detects the 2.0-psi or greater pressure changes from
the last transmission.
If the pressure change of 2.0 psi or greater was an increase of pressure, the
sensor shall not react to it.
Stationary Mode
While the sensor/transmitter in the Stationary Mode, it shall satisfy the
following requirements. The sensor/transmitter shall transmit an instantaneous
measured data, if a pressure change of 2.0 psi from the last transmission or
greater has occurred with respect to the following conditions. If the pressure
change was a decrease of pressure, the sensor/transmitter shall transmit
immediately every time it detects the 2.0-psi or greater pressure changes from
the last transmission.
If the pressure change of 2.0 psi or greater was an increase of pressure, the
silent period between the RPC transmission and the last transmission shall be
30.0 seconds, and the silent period between the RPC transmission and the next
transmission (Normal scheduled transmission or another RPC transmission) shall
also be 30.0 seconds, to be in compliance of FCC Part 15.231.
Factory Mode
The factory mode is the mode that the sensor shall transmit more often in the
factory to assure the programmability of the sensor ID during the
manufacturing process.
Off Mode
This Off Mode is only for production parts sensors that are used for the
builds during the production process and not in the service environment.
LF Initiation
The sensor/transmitter must provide data upon the presence of an LF signal.
The sensor must react (Transmit and provide data) no later than 150.0 ms after
the LF data code has been detected at the sensor. The sensor/transmitter must
be sensitive (As sensitivity is defined in Table 1) and able to detect the LF
field.