Infrared / Ultrasound
- The infrared or ultrasound remote central locking system consists of a transmitter handset (emitter), a receiver located in the vehicle to ensure a line of sight operation and an interface to the central locking control and other associated modules.
- The range of operation can vary dramatically from as little as two feet in very bright sunlight to as much as 15-20 feet in shadow conditions. Some bright lights, particularly fluorescent tubes, can reduce the operational range considerably.
- When a transmitter handset is aimed towards the receiver and operated a code signal is transmitted which matches the code in the receiver decoder. This coded signal can consist of a 32 bit binary code, which can allow for up to 4 million separate different combinations.
- On recognizing the correct code, the receiver decoder transmits the required lock or unlock signal to the central locking control module and also a signal to the alarm system control module if fitted
Radio frequency
- The radio frequency system is broadly similar in operation to the infrared or ultrasound system but with the added advantage that it functions over greater distances, 100-150 feet is quite normal, and does not have to comply with the line of sight requirement of the previous type. Most radio frequency remote transmitter systems operate on either the 315 MHz or 433 MHz frequency band.
- In some locations government departments can also use communications equipment on or near these frequency bands so interference can sometimes be experienced and in extreme cases it may be impossible to lock or unlock the vehicle using the remote transmitter.
- Vehicle manufacturers have been encouraged to improve the design of their systems to make them less susceptible to interference.
Synchronization
- This procedure is used on remote transmitters which have a scrolling random code. The remote transmitter operation can cease to function as a result of excessive button operations while the vehicle is out of range or when the batteries have been replaced.
Automotive and Commercial Locksmith
6105 Johnson Street
Hollywood, FL 33024
Phone: 1.954.347.9566
Website: AutomotiveAndCommercialLocksmith.com
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