Owner's Guide

Wednesday, May 12, 2004
TUV Product Services
10040 Mesa Rim Road
San Diego, CA 92121
RE: FCC ID EZSDEI487
Dear Sir or Madam,
This letter is to address the following for the 487VPX transceivers:
1. Learn routine for replacement transmitters
2. System transmission frequency range
3. Data transmission duty cycle description
4. Manuals
1. Refer to installation guide pages 35 to 38.
2. This transmitter is a single frequency device. It has a crystal controlled PLL which generates the
RF carrier. The crystal based oscillator can maintain a center frequency of 433.92MHz within a
+/-35KHz tolerance. The receiver operated by this transmitter is a single band receiver tuned to
433.92MHz and only capable of receiving this frequency.
3. The 487VPX is a data transmission device. Its protocol consists of 12 preamble bits (400us each)
and 66 data bits (400us or 800us each, they are random) for a total of 78 bits. So the calculation
for the duty cycle becomes:
(12 x 400us)+(66x800us)= 57.60ms within a 100ms period
The worst case scenario calculation is assured by the fact that we used 800us for all 66 data bits
as they can be either 400us or 800us.
4. There are no dedicated manuals for this device. The 487VPX transceiver is part of several car
alarm and remote start systems. Included are the installation and owner’s guides for the system
with the most features which is representative of other, less feature rich systems. The owner’s
guide of all systems have a section covering the operation of the transceiver. Please refer to
pages 5 to 12 in the owner’s guide.

Summary of content (51 pages)