FCC ID: KR55WK45032 User Manual / Functional Description of the Siemens RF Transmitter 5WK4 5032 315 MHz Language: English File: s:\postzula\vw\kessy\func_5wk45032_e page 1 of 4 FCC ID: KR55WK45032 General description of the RF transmitter The 315 MHz RF remote control system consisting of a RF transmitter and a RF receiver mounted within the control unit. The RF transmitter is mechanically integrated in the head of the key. This transmitter is used to transmit an information for locking or unlocking the vehicle by an unidirectional RF transmission line for normal remote operation by pressing a button. For passive access functionality the transmitter is able to reply to an inductive command with sending a remote telegramme. In general the following functions are provided by pressing the buttons:
- Lock the car
- Unlock the car
- Unlock trunc Additional the following functions are provided (Keyless Entry/Go Functions):
- Lock/Unlock the car
- Start/Stop the engine Power supply The transmitter is provided with 1 Lithium battery (CR2032) that gives a tension of feeding of +3V. The battery inversion is protected mechanically. Buttons There are three buttons which enable to lock, unlock the doors and unlock the trunk. During activation, the button is forced to the ground via a pull-up within the microcontroller. LED The LED is turned on between transmission blocks. File: s:\postzula\vw\kessy\func_5wk45032_e page 2 of 4 FCC ID: KR55WK45032 Oscillator The oscillator is of PLL type. The operating frequency is about 315 MHz 75 kHz. Mechanical design The mechanical of the transmitter is composed of four parts:
the superior shell the inferior shell metal insert battery support (mechanical protection to afford battery inversion) The battery placement is integrated in the inferior shell. Technical data Carrier frequency Output Power Type of modulation Method of frequency generation Number of channels Baudrate Power supply Type of battery Transmission range 315 MHz 75 kHz
< -18 dBm (carrier frequency) ASK Crystal 1 2 k Baud 3 Volt Lithium typical 10 meters File: s:\postzula\vw\kessy\func_5wk45032_e page 3 of 4 FCC ID: KR55WK45032 Typical usage pattern 27 lock / unlock operations in 24 hours with a typical transmission duration of 500 milliseconds Transmitter ON 13,5 seconds / 24 hours Transmitter OFF 86.386,5 seconds / 24 hours Duty Cycle: TON / T (ON+OFF) x 100% = 13,5 / 86.400 x 100 % = 0,015 %
Block diagram of the transmitter Buttons Power LED C Transponder /
inductive receiver RF stage Antenna Label design Siemens 315 MHz, 5WK4 5032 3D0 959 753 KWJJ FCC ID: KR55WK45032 CAN: xxx xxx xxxx Setup of homologation testing samples For homologation testing the testing samples are equipped with continuous transmission mode. After inserting the battery the transmitter starts continous transmission until the battery is removed. These special function have only been implemented for the testing related to radio homologation. This procedure does not correspond to the standard mode of operation!!!
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