102893 Key Fob Owner’s Manual
Theory of Operation
The Key Fob Transmitter combines a high-performance synthesized transmitter to form a highly reliable, yet cost-effective RF
remote control transmitter. The transmitter’s advanced synthesized architecture delivers superior stability and frequency
accuracy while minimizing the effects of temperature and body proximity.
The Key Fob operates in the following manner: when a button is pressed on the Key Fob, power is applied to the internal
circuitry and the encoder IC is enabled. The encoder then detects the logic states of the button data lines. The encoder data is
used to modulate the transmitter, which, through the antenna, conveys the data into free space. The transmission cycle
continues until the button is released. On the receiver side, a decoder IC is used to check the transmitter’s address bits against
the address saved in memory. If a match is confirmed, and if the decoder has permission to recognize the specific button being
pressed, the decoder’s outputs are set to replicate the transmitter’s button states. These outputs can then be used to activate
external circuitry required by the application
Setting the Transmitter Address
The transmitter address is set at the factory or by the OEM using the final device and the end user should not attempt to
modify this value, attempts to do so may render the Key Fob useless.
Button Assignments
The Key Fob is available in five button configurations. Those configurations are determined by the receiving hardware and
cannot be modified.
Contention Considerations
It is important to understand that only one transmitter at a time can be activated within a reception area. While the
transmitted signal consists of encoded digital data, only one carrier of any particular frequency can occupy airspace without
contention at any given time. If two transmitters are activated in the same area at the same time, then the signals will interfere
with each other and the decoder will not see a valid transmission, so it will not take any action.
Battery Replacement
The transmitter utilizes a standard CR2032 lithium button cell. In normal use, it provides several years of operation. Access for
replacement is accomplished by unscrewing the two halves of the Key Fob. Once the unit is open, remove the battery by sliding
it out from beneath the retainer.
There may be the risk of explosion if the battery is replaced by the wrong type. Replace it with the same type of battery while
observing the same polarity, with the positive contact facing out and away from the printed circuit
INSTRUCTION TO THE USER
This device complies with Part 15 of the FCC Rules and Industry Canada license-exempt RSS standard(s). Operation of this device is
subject to the following two conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received, including interference that may cause undesired operation.
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment
generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause
harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off
and on, the user is encouraged to try to correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
• Consult the dealer or an experienced radio / TV technician for help.
The user is cautioned that changes and modifications made to the equipment without the approval of manufacturer could void the
user’s authority to operate this equipment.
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radioexempts de licence. L'exploitation est
autorisée aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter
tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.
board.