WIRELESS MADE SIMPLE
®
HS LONG-RANGE HANDHELD TRANSMITTER DATA GUIDE
DESCRIPTION
®
The Linx OTX-***-HH-LR8-HS Long-Range
Handheld Transmitter is ideal for general-
purpose remote control and command
applications which require high security and
long transmission distances. This unit has been
pre-certified for FCC Part 15, Industry Canada,
and European CE (433MHz only) compliance,
reducing costs and time to market. Available in
315, 418 (standard), or 433.92MHz, this small
remote has a transmission range of up to 1,000
feet when combined with an LR or LT Series
module. The transmitter unit can be configured
with 1 to 8 buttons and the keypad and labeling
can be modified to meet specific OEM customer
requirements.
Security
is
dramatically
enhanced by the on-board HS Series encoder,
which uses Cipherlinx™ technology, a high-
security encryption algorithm and wireless
protocol. When paired with an HS Series
decoder, transmitter identity can be determined
and button permissions established. The unit
uses a single 3V CR2032 lithium button cell.
CipherLinx
Technology
1.375"
R 0.2"
2.00"
2.81"
1.35"
1.62"
0.20"
0.60"
Figure 1: Package Dimensions
O
FF
2
3
ON
1
Ligh
ts
O
N
ON
D
O
FF
Poo
l
Spa
ON
O
FF
O
N
4
C
A
B
ON
FASCO
O
N
FEATURES
FCC, Canada, and CE pre-certified
Highly secure, encrypted transmission
1 to 8 buttons
Customizable keypad
OEM Configurations
With a one-time NRE and
minimum order, Linx can configure
the keypad and label areas to
meet your specific requirements.
Contact Linx for details.
APPLICATIONS INCLUDE
Secure Remote Control
Keyless Entry
Garage / Gate Openers
Lighting Control
Call Systems
Home / Industrial Automation
Wire Elimination
ORDERING INFORMATION
PART #
DESCRIPTION
OTX-***-HH-LR8-HS-xxx HS Long-Range Transmitter
MDEV-***-HH-LR8-HS
HH-LR8 Master Development System
*** = 315, 418 (Standard), 433.92MHz
xxx = Reserved for custom colors. Leave blank for standard black
Revised 1/28/08
ELECTRICAL SPECIFICATIONS
Parameter
POWER SUPPLY
Operating Voltage
Supply Current
Power-Down Current
TRANSMITTER SECTION
Transmit Frequency Range:
OTX-315-HH-LR8-HS
OTX-418-HH-LR8-HS
OTX-433-HH-LR8-HS
Center Frequency Accuracy
ENVIRONMENTAL
Operating Temperature Range
–
–
Designation
V
CC
I
CC
I
PDN
F
C
–
–
–
-50
-40
315
418
433.92
–
–
–
–
–
+50
+85
MHz
MHz
MHz
kHz
°C
–
–
–
–
1
Min.
2.1
–
–
Typical
3.0
3.4
5.0
Max.
3.6
–
–
Units
VDC
mA
nA
Notes
–
–
1
SECURITY OVERVIEW
The HS Long-Range Handheld transmitter uses the HS Series encoder, which is
based on Cipherlinx™ technology. CipherLinx™ is a high-security encryption
algorithm and wireless protocol designed for remote control and remote keyless
entry applications. It provides a much greater level of security and many more
features than older technologies on the market, such as fixed address or “rolling
code” systems. Additionally, the CipherLinx™ protocol is much more advanced
than the simple PWM method employed by many systems. By utilizing an
advanced serial protocol, CipherLinx™ is able to offer superior noise immunity,
greater range, and greater link reliability, all of which are key factors in a wireless
system.
CipherLinx™ never sends or accepts the same data twice, never loses sync, and
changes codes with every packet, not just every button press. The encryption
that is used in CipherLinx™ is based on the Skipjack cipher developed by the
U.S. National Security Agency (NSA), and is widely considered one of the most
secure ciphers available. The CipherLinx™ algorithm has been evaluated by
Independent Security Evaluators (ISE), a company that has testified before
Congress as experts on electronic security. They concluded that “In short, the
CipherLinx™ protocol in the HS Series is well-designed and is an excellent
choice for applications requiring a secure unidirectional link.”
In addition to this high level of security, CipherLinx™ also offers a number of
features that are unique among remote control products. These include a large
number of data lines, internal key generation, “button level” control permissions,
an optional encoder PIN, as well as the ability for the decoder to identify the
originating encoder.
CipherLinx™ is based on the NSA-designed cipher Skipjack. Skipjack is a block
cipher that has 80-bit keys and 64-bit data blocks. Since each packet is longer
that 64 bits, Skipjack must be employed in an encryption mode. The particular
encryption mode chosen for CipherLinx™ is based on the CMC encryption
mode, so that the resulting cipher is a special kind of function known as a “strong
PRP” (sPRP). The encryption mode uses several invocations of Skipjack to
encrypt the 128 bits in each message. The definition of these terms is quite
involved, but more details can be found in ISE’s evaluation report at
www.cipherlinx.com.
The HS Series uses a 40-bit counter to change the appearance of each
message. This large counter value and the timing associated with the protocol
ensure that the same message is never sent twice and prevents the encoder
from ever losing sync with the decoder.
The user generates the key with the decoder through multiple button presses.
This ensures that the key is random and chosen from among all 2
80
possible
keys. Since all of the keys are created by the user and are internal to the part,
there is no list of numbers anywhere that could be accessed to compromise the
system.
The user or manufacturer may also set “button level” Control Permissions.
Control Permissions determine how the decoder will respond to the reception of
a valid command, either allowing the activation of an individual data line or not.
The decoder is programmed with the permission settings during set-up, and
those permissions are retained in the decoder’s non-volatile memory.
Page 3
Notes
1. Characterized, but not tested
THEORY OF OPERATION
The OTX-***-HH-LR8-HS Long-Range Handheld Transmitter combines an LR
Series transmitter and an antenna with an on-board HS Series encoder to form
a highly reliable and secure RF remote-control transmitter. The LR Series
transmitter is a low-cost, high-performance synthesized OOK transmitter. Its
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 an encrypted message
that is output to the transmitter module. This cycle continues until the button is
released. The encoder data is used to modulate the transmitter, which conveys
the data into free space through the antenna. Once data is received, a decoder
IC is used to decrypt the transmitter’s commands. If decryption is successful, the
decoder’s outputs are set to replicate the transmitter’s button states. These
outputs can then be used to activate whatever external circuitry is required by the
application.
The transmitter is compatible with the LT 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 an HS 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.
Page 2
TYPICAL SYSTEM SETUP
The HS Series Long-Range Handheld Transmitter is intended to make user
setup straightforward while ensuring the highest possible security. This inherent
ease of use can be illustrated by a typical user setup. The Typical Applications
section of the HS Series Decoder Data Guide shows the circuit schematics on
which the receiver examples are based.
1. Create and exchange a key from a decoder to the handheld transmitter
The handheld transmitter includes an on-
board infrared receiver designed to
optically receive the decoder’s key
transmission. Sending the key in this
manner preserves security while avoiding
the need for a hardwire connection.
USING THE OPTIONAL KEYPAD PIN
For higher security applications, the HS Series encoder has the option to set a
Personal Identification Number (PIN) to control access to the encoder. This PIN
is a four-button combination of the eight buttons which must be entered before
the transmitter will send any commands. It will need to be re-entered after fifteen
minutes of inactivity. If no PIN is created, then the transmitter will activate as
soon as a button is pressed.
Creation of a keypad PIN
1. Use a paper clip to press the CREATE_KEY button on the back of the
transmitter. The MODE_IND LED will begin flashing until either a PIN is
successfully entered or fifteen seconds has passed.
2. To enter the PIN, press a sequence of any four buttons. The MODE_IND will
stop flashing and the PIN will be created.
3. To cancel Create PIN Mode prior to the fourth entry, either wait for the fifteen
second timeout to pass or press the CREATE_KEY button. The MODE_IND
LED will stop flashing and no PIN will be created.
4. If a new KEY is created, the PIN will be automatically erased.
Using the PIN
1. The PIN is entered by pressing each button until all four entries have been
made. There is a maximum two-second time limit between entries, after which
the PIN must be re-entered in its entirety.
2. Once the PIN is successfully entered, the transmitter will be operational unless
it is inactive for fifteen minutes, in which case the PIN must be re-entered.
GET_KEY Button
The high security key is created and
Window
exchanged by placing the decoder in the
Create Key Mode. The decoder’s
MODE_IND LED will light to indicate that
CREATE_PIN
the decoder has entered Create Key
Button
Mode. The decoder’s CREATE_KEY
Figure 2: Button Access Holes
button is then pressed ten times to create
the key. After the tenth press, the MODE_IND LED will turn off and the decoder
will output the key via a 900nm infrared diode on the KEY_OUT line. A paper clip
is used to press the GET_KEY button on the back of the transmitter. Hold the
back of the transmitter near the decoder’s infrared diode within twenty seconds.
Once the key has been transferred, the MODE_IND LEDs on the transmitter and
decoder illuminate to indicate success.
2. Establish Control Permissions
Next, the user defines which buttons on the transmitter will be acknowledged by
the decoder. The HS Series Control Permissions allow each transmitter in a
system to activate different data lines. This is especially useful in applications
where differing user access or activation capabilities are desired.
Consider this practical example: a three-door garage houses Dad’s Corvette,
Mom’s Mercedes, and Son’s Yugo. With most competitive products, any user’s
keyfob could open any garage door as long as the addresses match. In an HS-
based system, the keyfobs could easily be configured to open only certain doors
(guess which one Son gets to open!).
Setting the control permissions is intuitive. The user presses the decoder’s
LEARN button. The decoder’s MODE_IND LED will start flashing and the user
simply presses the handheld transmitter buttons that will be recognized. Control
Permissions are stored when the LEARN button is pressed again or
automatically after seventeen seconds.
There are other powerful options, such as programming a user PIN or copying a
decoder, but these two steps are all that is required for a typical setup.
MODE_IND
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 uses a standard CR2032 lithium
button cell. In normal use, it will provide 1 to 2 years
of operation. To replace the battery, remove the
access cover by pressing firmly on the label area and
sliding it off. Once the unit is open, remove the
battery by sliding it from beneath the holder. 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 polarity shown in the
adjacent figure.
Battery Access
+
Figure 3: Battery Access
Page 4
Page 5
OTX-***-HH-LR8-HS BUTTON ASSIGNMENTS
This diagram illustrates the relationship between the button locations and
encoder data lines.
COMPLIANCE REQUIREMENTS
The OTX-***-HH-LR8-HS has been pre-certified by Linx Technologies for FCC
Part 15 and Industry Canada RSP-100 compliance. The 433.92MHz version has
also been tested for CE compliance for use in the European Union. The 315MHz
and 418MHz versions are not legal for use in Europe.
LABELING / INSTRUCTION REQUIREMENTS
The OTX-***-HH-LR8-HS Long-Range Handheld Transmitter has already been
labeled in accordance with FCC, Industry Canada, and CE regulations in effect
as of the date of this document. No further labeling of the unit is needed;
however, it is necessary to include the following statement in the end product’s
instruction manual or insert card for FCC compliance. Industry Canada only
requires the shaded portion. The EU does not require a statement.
INSTRUCTION TO THE USER
This device complies with Part 15 of the FCC Rules.
Operation of this device is subject to the following two conditions:
(1) This device may not cause harmful interference, and
Figure 4: OTX-***-HH-LR8-HS Button Assignments
D6
D4
D2
D0
D7
D5
D3
D1
(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.
This equipment has been certified to comply with the limits for a Class B
computing device, pursuant to FCC Rules. In order to maintain compliance with
FCC regulations, shielded cables must be used with this equipment. Operation
with non-approved equipment or unshielded cables is likely to result in
interference to radio and TV reception. 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.
ASSEMBLY DIAGRAM
418MHz
FCC ID: OJM-OTX-XXX-LRMSA
IC: 5840A-LRMSXXXA
Figure 5: OTX-***-HH-LR8-HS Assembly
Place the above statement in the instruction manual or insert card.
Page 6
Page 7
TYPICAL APPLICATIONS
The signal sent by the HS Long-Range Transmitter can
be received by an LR Series receiver module or the LT
Series transceiver module. The outstanding sensitivity of
the LR Series receiver offers the best range when used
with a Linx OEM transmitter. The receiver module is then
connected directly to an HS Series decoder, which will
decrypt the transmitted signal.
When a button is pressed on the transmitter, a
corresponding line on the decoder will go high. This can
then be connected to external circuitry to perform
whatever function is required by the application.
The transmitter and decoder must be synchronized
before they can work together. This is done by creating
a new encryption key in the decoder, then transferring it
to the transmitter as previously described.
LICAL-DEC-HS001
ANT1
ANTENNA
U2
9
8
7
6
5
4
3
2
1
SM1
COM
SW8
SW7
SW6
SW5
SW4
SW3
SW2
SW1
VCC
4
3
4
3
4
3
4
DPAK-X2
DPAK-X2
3
DPAK-X2
VCC
VCC
GND
GND
100k
LICAL-DEC-HS001
GND
The TX_ID line will output a
Figure 6: LR Receiver and HS Decoder Schematic
number associated with the
handheld transmitter from which the signal originated. Linx Application Note AN-
00156 shows how to use this feature.
R15
9.1M
VCC
COUT
CIN-
CIN+
8
7
6
5
VCC
220
B1
BAT-LINX2032
As the name suggests, “Send
Copy” allows the users and
associated Control Permissions
of one HS Series decoder to be
transferred to another. This is
useful if the same users and
permissions are desired at
multiple locations, such as the
front door and back door of a
building. Please see the HS
Series Decoder Data Guide for
more information on this
feature.
GND
Set
for FCC
Compliance
GND
GND
GND
GND
GND
GND
D1
LED
RXM-***-LR
R13
LICAL-ENC-MSHS
VCC
U1
D6
D7
SEL_BAUD
SEL_TIMER
GND
GND
KEY_IN
TX_CNTL
DATA_OUT
MODE_IND
1
2
3
4
5
6
7
8
NC
NC
NC
GND
VCC
PDN
RSSI
DATA
ANT
GND
NC
NC
NC
NC
NC
NC
16
15
14
13
12
11
10
9
1
2
3
4
TXM-***-LR
TX1
LADJ/VCC
DATA IN
GND
GND
D5
D4
D3
D2
VCC
VCC
D1
D0
SEND
CREATE_PIN
The decoder has several
unique features, such as Send
Copy, and TX_ID.
RF OUT
PDN
GND
VCC
VCC
R3
200
VCC
GND
100k
220
R19
10k
IR1
PS1102
From Copy Input Port
100k
R22
R20
51k
GND
VCC
100k
GND
1
2
3
4
5
6
7
8
9
10
D6
D7
SEL_BAUD
SEND_COPY
GND
GND
COPY_IN
CREATE_KEY
KEY_OUT
MODE_IND
D5
D4
D3
D2
VCC
VCC
D1
D0
DATA_IN
LEARN
20
19
18
17
16
15
14
13
12
11
4.7uF
10pF
C2
C3
R18
9.1M
R21
100k
C5
0.01uF
GND
VCC
GND
GND
GND
The adjacent figure shows a schematic for a typical receiver application. The
handheld transmitter is set to 4,800bps, so the decoder’s SEL_BAUD line will
need to be tied low.
DPAK-X2
U3
U4
U5
GND
100K
1
2
1
2
1
2
1
2
R2
100K
R4
100K
R5
100K
R6
100K
R7
100K
R8
100K
R9
RXM-***-LR
100K
R10
100K
R11
8
7
6
5
R1
100k
S1
TLV2302
U6
AOUT
AIN-
AIN+
GND
C1
4.7uF
R16
9.1M
Data guides for the LR Series receiver, the HS encoder, and the HS decoder can
be found on the Linx Technologies website at www.linxtechnologies.com.
VCC
9.1M
R17
GND
VCC
R14
5.1M
C4
4.7uF
S2
Figure 7: OTX-***-HH-LR8-HS Schematic
Page 8
Page 9
GND
GND
GND
GND
VCC
1
2
3
4
GND
VCC
GND
FPGA/CPLD
