SL57L0 – TECNHICAL INFORMATION
1. General Technical Description
1-1. Intended use and Operation instructions
This equipment constitutes a Keyless Start System comprising a portable transmitter
and a control unit including receiver installed in a inside of the vehicle.
This system is a radio frequency apparatus which distantly controls the locking and
unlocking of motor vehicle door locks, unlock, trunk lid and panic alarm by operating a
portable transmitter with 3 or 4 control buttons.
The transmitter is activated by loading a battery cell in it.
The Specification of operation is shown below.
By pressing the “LOCK” or “UNLOCK” or ”TRUNK”button for least 30 milliseconds,
the duration requird for the transmitter and the receiver to recognize the state of the
switch as ON or OFF, the vehicle’s door lock actuators are energized, and flash the
hazard lamps for indicator purpose.
By pressing one of the buttons, the radiation occurs in the form of coded signals that
are received by the control unit installed in the vehicle. The control unit wakes-up,then
compares the received ID code with the pre-stored ID code in its non-volatile memory,
then activates the door lock actuators upon coincidence of both codes.
The coded signals are consisted by the wake-up sinal(A) and the ID signal(B) shown in
section 1-3.
The ID signal is consisted by unique ID portion and function portion which directs the
control units “LOCK” or “UNLOCK” or “TRUNK” status.
If two or more buttons pressed simultaneously, the transmitter stops the signal radiation
immediately.
When one of button is pressed for long duration, at least 404 millisecond, following the
wake-up signal(A) signal(B), the transmitter will radiates other signal(C), however any
function is assigned at the control unit to this signal(C).
The signal radiated is consisted by a header code(A), which is 3.2 millisecond pulses
with 50% duty, continued for 243.2 milliseconds, to wake-up the control unit, and
followed by ID codes, a 24 bit unique ID portion combined with 4 bit function codes,
which represents above(B) code.
When the duration is continued at least 15 second, the transmitter radiates stop code,
shown Fig1-3, then ceases the radiation. By receiving the stop code, the control unit
will stops any activity and go to sleep mode.
The transmitter and receiver communication is made on frequency f=315 MHz, and the
modulation is FSK, corresponding to binary digit 0 and 1.
The timing diagrams are given in section 1-3.
