Linx SI Keyfob Instruction Manual

SI Keyfob
Transmitter
Data Guide

Warning: Some customers may want Linx radio frequency (“RF”)
products to control machinery or devices remotely, including machinery
or devices that can cause death, bodily injuries, and/or property
damage if improperly or inadvertently triggered, particularly in industrial
settings or other applications implicating life-safety concerns (“Life and
Property Safety Situations”).
NO OEM LINX REMOTE CONTROL OR FUNCTION MODULE
SHOULD EVER BE USED IN LIFE AND PROPERTY SAFETY
SITUATIONS. No OEM Linx Remote Control or Function Module
should be modified for Life and Property Safety Situations. Such
modification cannot provide sufficient safety and will void the product’s
regulatory certification and warranty.
Customers may use our (non-Function) Modules, Antenna and
Connectors as part of other systems in Life Safety Situations, but
only with necessary and industry appropriate redundancies and
in compliance with applicable safety standards, including without
limitation, ANSI and NFPA standards. It is solely the responsibility
of any Linx customer who uses one or more of these products to
incorporate appropriate redundancies and safety standards for the Life
and Property Safety Situation application.
Do not use this or any Linx product to trigger an action directly
from the data line or RSSI lines without a protocol or encoder/
decoder to validate the data. Without validation, any signal from
another unrelated transmitter in the environment received by the module
could inadvertently trigger the action.
All RF products are susceptible to RF interference that can prevent
communication. RF products without frequency agility or hopping
implemented are more subject to interference. This module does not
have a frequency hopping protocol built in.
Do not use any Linx product over the limits in this data guide.
Excessive voltage or extended operation at the maximum voltage could
cause product failure. Exceeding the reflow temperature profile could
cause product failure which is not immediately evident.
Do not make any physical or electrical modifications to any Linx
product. This will void the warranty and regulatory and UL certifications
and may cause product failure which is not immediately evident.
!Table of Contents
1 Description
1 Features
1 Applications
1 OEM Congurations
2 Ordering Information
2 Electrical Specications
3 Theory of Operation
4 Setting the Transmitter Address
4 Button Assignments
5 Contention Considerations
5 Battery Replacement
5 Assembly Diagram
6 Compliance Requirements
6 Labeling / Instruction Requirements
8 Typical Applications
10 Resources
11 Notes

––
1
Description
The Linx SI Series Keyfob transmitter is
ideal for remote control and command
applications. Available in 418 (standard)
or 433.92MHz versions, it has been
pre-certified for FCC Part 15, Industry
Canada, and European CE (433MHz)
compliance. This dramatically reduces
development cost and time to market.
The high-performance synthesized design
provides superior frequency accuracy and
minimizes body proximity effects. When
combined with a Silicon Labs Si4355
receiver, the Keyfob can operate at
distances of up to 1000 feet. Ease of use
and security are dramatically enhanced
by the use of Silicon Labs Ember
One-Way Link protocol with AES-128
encryption. The Keyfob is available with 1
to 5 buttons and can be custom labeled.
Features
• FCC, IC and CE pre-certified
• Long range
• Simple user setup
• Factory preset unique address
• 1 to 5 buttons
• Compact, stylish package
Applications
• General remote control
• Keyless entry
• Garage / gate openers
• Lighting control
• Home / industrial automation
• Wire elimination
SI Keyfob Transmitter
Data Guide
Revised 10/16/14
2.23"
1.00"
0.45"
1.37"
S4
S2
S1 S3S5
Figure 1: Package Dimensions
Figure 2: Keyfob Button Configurations
OEM Congurations
With a one-time NRE and
minimum order, Linx can
configure the keypad and label
areas. Contact Linx for details.

–– – –
2 3
Ordering Information
Part Number Description
OTX-***-HH-KF#-SI-xxx SI Keyfob Transmitter
MDEV-***-HH-KF#-SI SI Keyfob Development System
*** = 418 (Standard) or 433.92MHz
xxx = Color (Leave blank for standard black)
WHT = White
CRE = Red
CGY = Gray
Keyfob Electrical Specifications
Parameter Designation Min. Typ. Max. Units Notes
Power Supply
Operating Voltage VCC 2.1 3.0 3.6 VDC
Supply Current lCC 3.4 mA
Power-Down Current lPDN 5.0 nA 1
Transmitter Section
Transmit Frequency Range FC
OTX-418-HH-KF#-SI 418 MHz
OTX-433-HH-KF#-SI 433.92 MHz
OTA Modulation 2FSK
Center Frequency Accuracy –50 +50 kHz
Frequency Deviation 59.05 kHz
Data Rate 9,600 bps
Environmental
Operating Temperature Range –40 +85 °C 1
1. Characterized, but not tested
Electrical Specications
Ordering Information
Figure 3: Ordering Information
Figure 4: Electrical Specifications
Theory of Operation
The SI Series Keyfob Transmitter combines a high-performance
synthesized SoC transmitter with an on-board microcontroller input
interpretation. The transmitter’s advanced synthesized architecture delivers
superior stability and frequency accuracy while minimizing the effects of
temperature and body proximity.
The Keyfob operates in the following manner: when a button is pressed
on the Keyfob, the transmitter and microcontroller are woken from sleep
mode. The microcontroller detects the logic states of the button data
lines. The button data line logic states are sent from the microcontroller
to the transmitter as a serial data packet. The transmitter SoC generates
a 42-byte encrypted packet and transmits a three-packet burst for each
button press throught the antenna and into fre space. On the receiver
side, a Si4355 checks the preamble, the sync bytes and the CRC of the
transmitted packet. If the packet is OK the receiver responds to the button
logic state data in the manner programmed into the receiver by the end
user.
The transmitter is compatible with the Silicon Labs Si4355 receivers using
the Silicon Labs Ember One-Way Link protocol.

–– – –
4 5
Transmitter Address
The unique address for each unit is preprogrammed in the Silicon Labs
radio IC during manufacturing and cannot be changed or modified by
the end user. A 16-byte pairing key is programmed into the transmitter at
the factory and is shared with the associated receiver during the pairing
process.
Button Assignments
The Keyfob is available in five button configurations. Those configurations
and the corresponding switch numbers are shown in Figure 5. The table
shows which encoder data line has been assigned to each switch. When a
button is pressed, the data line goes high, causing the corresponding data
line on the decoder to go high if the address has been learned.
S4
S2
S1 S3S5
S5
S2
S5
S4
S4
S2
S4
S1 S3
S2
Button Data Line
S1 D0
S2 D1
S3 D2
S4 D3
S5 D4
Figure 5: OTX-***-HH-KF#-MS Button Assignments
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 1 to 2 years of
operation. Access for replacement is accomplished
by gently prying apart the two halves of the Keyfob at
the seam (fingernails or a coin will do). 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 polarity shown in
Figure 6.
Assembly Diagram
Battery
Figure 6: Battery Access
Figure 7: OTX-***-HH-KF#-MS Assembly

–– – –
6 7
Labeling / Instruction Requirements
The transmitter has been pre-certified for FCC Part 15 and Industry
Canada license-exempt RSS standards for an intentional radiator. The
433.92MHz version has also been tested for CE compliance for use in
the European Union. The 418MHz version is not legal for use in Europe.
It has already been labeled in accordance with FCC, Industry Canada
and CE regulations. 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. EU does not require a statement.
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modications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.

–– – –
8 9
Resources
Support
For technical support, product documentation, application notes, regulatory
guidelines and software updates, visit www.linxtechnologies.com
RF Design Services
For customers who need help implementing Linx modules, Linx offers
design services including board layout assistance, programming,
certification advice and packaging design. For more complex RF solutions,
Apex Wireless, a division of Linx Technologies, creates optimized designs
with RF components and firmware selected for the customer’s application.
Call [phone] ([phone] if outside the United States) for
more information.
Antenna Factor Antennas
Linx’s Antenna Factor division has the
industry’s broadest selection of antennas
for a wide variety of applications. For
customers with specialized needs, custom antennas and design services
are available along with simulations of antenna performance to speed
development. Learn more at www.linxtechnologies.com.
by
Notes

Linx Technologies
159 Ort Lane
Merlin, OR, US 97532
Phone: [phone]
Fax: [phone]
www.linxtechnologies.com
Disclaimer
Linx Technologies is continually striving to improve the quality and function of its products. For this reason, we
reserve the right to make changes to our products without notice. The information contained in this Data Guide
is believed to be accurate as of the time of publication. Specifications are based on representative lot samples.
Values may vary from lot-to-lot and are not guaranteed. “Typical” parameters can and do vary over lots and
application. Linx Technologies makes no guarantee, warranty, or representation regarding the suitability of any
product for use in any specific application. It is Customer’s responsibility to verify the suitability of the part for the
intended application. At Customer’s request, Linx Technologies may provide advice and assistance in designing
systems and remote control devices that employ Linx Technologies RF products, but responsibility for the ultimate
design and use of any such systems and devices remains entirely with Customer and/or user of the RF products.
LINX TECHNOLOGIES DISCLAIMS ANY AND ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. IN NO EVENT SHALL LINX TECHNOLOGIES BE LIABLE FOR ANY CUSTOMER’S OR
USER’S INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR RELATED TO THE DESIGN OR USE
OF A REMOTE CONTROL SYSTEM OR DEVICE EMPLOYING LINX TECHNOLOGIES RF PRODUCTS OR FOR ANY
OTHER BREACH OF CONTRACT BY LINX TECHNOLOGIES. CUSTOMER AND/OR USER ASSUME ALL RISKS
OF DEATH, BODILY INJURIES, OR PROPERTY DAMAGE ARISING OUT OF OR RELATED TO THE USE OF LINX
TECHNOLOGIES RF PRODUCTS, INCLUDING WITH RESPECT TO ANY SERVICES PROVIDED BY LINX RELATED
TO THE USE OF LINX TECHNOLOGIES RF PRODUCTS. LINX TECHNOLOGIES SHALL NOT BE LIABLE UNDER ANY
CIRCUMSTANCES FOR A CUSTOMER’S, USER’S, OR OTHER PERSON’S DEATH, BODILY INJURY, OR PROPERTY
DAMAGE ARISING OUT OF OR RELATED TO THE DESIGN OR USE OF A REMOTE CONTROL SYSTEM OR DEVICE
EMPLOYING LINX TECHNOLOGIES RF PRODUCTS.
The limitations on Linx Technologies’ liability are applicable to any and all claims or theories of recovery asserted
by Customer, including, without limitation, breach of contract, breach of warranty, strict liability, or negligence.
Customer assumes all liability (including, without limitation, liability for injury to person or property, economic loss,
or business interruption) for all claims, including claims from third parties, arising from the use of the Products.
Under no conditions will Linx Technologies be responsible for losses arising from the use or failure of the device
in any application, other than the repair, replacement, or refund limited to the original product purchase price.
Devices described in this publication may contain proprietary, patented, or copyrighted techniques, components,
or materials.
© 2014 Linx Technologies. All rights reserved.
The stylized Linx logo, Wireless Made Simple, CipherLinx, WiSE and the stylized CL logo are trademarks of Linx Technologies.