User's Manual

Page 3
SETTING THE TRANSMITTER ADDRESS
The MS Compact Handheld Transmitter
allows the selection of one of
16,777,216 (2
24
) unique addresses. All
transmitters are supplied set to the
same address. To avoid contention with
other units or to create unique
relationships, the address can be
changed. This is accomplished by using
a paper clip or probe to press the
CREATE_ADDR button on the board
through the bottom hole in the back of
the case. When the button is depressed,
a LED will light up in the MODE_IND
window, indicating that the address is being created. The address will be
randomized for as long as the button is held down. When the button is released,
the randomized address is saved and the LED will begin flashing to indicate that
the Control Permissions may now be set. Press the buttons that the transmitter
will have the authority to access. Press the CREATE_ADDR button with the
paper clip again or wait 17 seconds for it to time out. The address and Control
Permissions are now set. The decoder will need to learn the address before it
will accept any transmissions. Please see the Typical Applications section of this
data guide or the MS Series Decoder Data Guide for details.
OTX-***-HH-CP8-MS BUTTON ASSIGNMENTS
This diagram illustrates the relationship between the button locations and
encoder data lines.
D6 D7
D4 D5
D2 D3
D0 D1
Page 2
Figure 2: CREATE_ADDR Button Access
Figure 3: OTX-***-HH-CP8-MS Button Assignments
THEORY OF OPERATION
The OTX-***-HH-CP8-MS Compact Handheld transmitter combines the LR
Series transmitter and an antenna with an on-board MS Series encoder to form
a simple, yet highly reliable RF remote-control transmitter. The LR Series
transmitter is a low-cost, high-performance synthesized ASK / OOK transmitter.
The transmitter’s synthesized architecture delivers outstanding stability and
frequency accuracy, while minimizing the effects of antenna port loading and
mismatching. This reduces or eliminates frequency pulling, bit contraction, and
other negative effects that are common to SAW-based transmitter architectures,
providing a significantly higher level of performance and reliability.
When a button is pressed on the transmitter, power is applied to the internal
circuitry and the encoder is enabled. The encoder then detects the logic states
of the button data lines. These states are formatted into a 2-word transmission
cycle that continues until the button is released. The encoder data is used to
modulate the transmitter that, through the antenna, conveys the data into free
space. Once data is received, a decoder IC is used to check the transmitter’s
address against an address saved in memory. If a match is confirmed, 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.
The transmitter is compatible with several Linx receiver products, including the
LC and LR product families. For applications where range is critical, the LR
Series receiver is the best choice due to its outstanding sensitivity. When the
transmitter is combined with an LR Series receiver and the MS Series decoder,
ranges of up to 1,000 feet are possible. Applications operating over shorter
distances will also benefit from the increased link reliability and superior noise
immunity provided by the LR Series receiver.
1. Characterized, but not tested
Notes
ELECTRICAL SPECIFICATIONS
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POWER SUPPLY
Operating Voltage V
CC
2.1 3.0 3.6 VDC –
Supply Current I
CC
– 3.4 – mA –
Power-Down Current I
PDN
– 5.0 – nA 1
TRANSMITTER SECTION
Transmit Frequency Range: F
C
OTX-315-HH-CP8-MS – 315 – MHz –
OTX-418-HH-CP8-MS – 418 – MHz –
OTX-433-HH-CP8-MS – 433.92 – MHz –
Center Frequency Accuracy – -50 – +50 kHz –
ENVIRONMENTAL
Operating Temperature Range – -40 – +85 °C 1