Linx Technologies CMD-KEYX-XXXA Keyfob Transmitter User Manual CMD KEYX xxx Manual 4 27 05
Linx Technologies Keyfob Transmitter CMD KEYX xxx Manual 4 27 05
Users Manual
DESCRIPTION
The Linx CMD-KEY#-xxx Remote Command
Keyfob is ideal for general-purpose remote
control and command applications. This unit
has been pre-certified for FCC Part 15,
Industry Canada, and CE (433MHz only)
compliance, reducing development costs and
time to market. Available in 315, 418, or
433.92MHz (418MHz standard), this stylish
and compact remote has a range of up to
1,000ft when combined with the LR Series
receiver. The keyfob can be configured with
1 to 5 buttons and the keypad and labeling
can be modified to meet specific customer
requirements. Selectable addressing
provides security and allows the creation of
up to 1024 distinct transmitter-receiver
relationships. The keyfob is available in
black, white, or transparent colors. The
transmission can be decoded using a
matching Linx Function Module, KH Series
receiver/decoder, or an LC or LR Series
receiver paired with a decoder IC or
microcontroller. The unit operates from a
single 3V CR-2032 lithium button cell.
FEATURES
FCC, Canada, and CE pre-certified
1 to 5 buttons
Small package
Customizable keypad
APPLICATIONS INCLUDE
General Remote Control
Keyless Entry
Garage / Gate Openers
Lighting Control
Call Systems
Home / Industrial Automation
Wire Elimination
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.
OEM KEYFOB TRANSMITTER DATA GUIDE
2.23"
1.00"
0.45"
1.37"
S4
S2
S1 S3S5
Revised 4/27/05
PART NUMBER DESCRIPTION
CMD-KEY#-xxx-*** Keyfob Transmitter
EVAL-xxx-KEY# Keyfob Evaluation System
# = Number of Buttons, 1 - 5
xxx = 315, 418 (Standard), 433.92 MHz
*** = Color Leave blank for standard Black
WHT = White CGY= Gray CBL = Blue
CRE = Red CPU = Purple
ORDERING INFORMATION
Figure 1: Physical Dimensions
WIRELESS MADE SIMPLE
Page 3Page 2
THEORY OF OPERATION
The CMD-KEY#-xxx Keyfob Command Unit combines the LR Series transmitter
with an on-board Holtek HT640 encoder IC to form a simple, yet effective, RF
remote-control transmitter. The LR 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 remote unit, power is applied to the internal
circuitry and the encoder IC is enabled. The encoder then detects the logic states
of the address lines and button data lines. These states are formatted into a
three-word transmission cycle that continues until the button is released. The
encoder data is used to modulate the transmitter, which, through the antenna,
conveys the data into free space. On the receiver side, a decoder IC or custom
microcontroller is used to check the transmitter's address bits against the
address settings of the receiving device. 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, LR, KH, and OEM product families. For applications where range is critical,
the LR Series receiver is the best choice due to its outstanding sensitivity. When
the keyfob transmitter is combined with an LR Series receiver and the HT658
decoder chip, ranges up to 1000 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.
SETTING THE TRANSMITTER ADDRESS
The keyfob allows the selection of one
of 1024 unique addresses. All keyfobs
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 cutting the traces with
a sharp object, such as an X-Acto knife.
The traces are accessed by removing
the rear cover.
If the trace is intact, the address line is
connected to ground, otherwise it is
floating. The receiver's address must match exactly in order for the units to
communicate. Application Note AN00300 describes in detail how to set the
address to match any of the receivers offered by Linx. This note can be found in
the Support section of the Linx web site.
BUTTON ASSIGNMENTS
The keyfob is available in five unique button configurations. Those configurations
and the corresponding switch numbers are shown in the figure below. The table
shows which encoder data line has been assigned to each switch. When a
button is pressed, the data line will go high, causing the corresponding data line
on the decoder to go high if the addresses match.
S4
S2
S1 S3S5
S5
S2
S5
S4
S4
S2
S4
S1 S3
S2
Figure 3: CMD-KEY#-xxx Button Assignments
Figure 2: DIP Switch Assignments
Button Data Line
S1 D0
S2 D1
S3 D2
S4 D3
S5 D4
ELECTRICAL SPECIFICATIONS
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POWER SUPPLY
Operating Voltage VCC 2.1 3.0 3.6 VDC –
Supply Current ICC –3.4 –mA –
Power-down Current IPDN –5–nA 1
TRANSMITTER SECTION
Transmit Frequency Range FC
CMD-KEY#-315 –315 –MHz –
CMD-KEY#-418 –418 –MHz –
CMD-KEY#-433 – 433.92 – MHz –
Center Frequency Accuracy –-50 –+50 kHz –
ENVIRONMENTAL
Operating Temperature Range – -40 – +85 °C1
1. Characterized, but not tested.
Notes
Page 5Page 4
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
(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.
Place the above statement in the instruction manual or insert card.
COMPLIANCE REQUIREMENTS
The CMD-KEY#-xxx 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 CMD-KEY#-xxx Remote Command Unit 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.
Figure 5: CMD-KEY#-xxx Assembly
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 remote unit utilizes a standard CR-2032 lithium
button cell. In normal use, it will provide 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 will do for this). Once the unit is
open, remove the battery by sliding it out from beneath
the retainer. Replace it with the same type of battery
while observing the polarity shown in the adjacent
figure.
ASSEMBLY DIAGRAM
Battery
+
Figure 4: Battery Access
V
CC
G
N
D
B1
T
OUC
HPA
D
S5
T
OUC
HPA
D
S4
T
OUC
HPA
D
S3
T
OUC
HPA
D
S2
T
OUC
HPA
D
S1
V
CC
V
CC
CU
T TRA
C
E F
OR
ADDRESS SELECT
G
N
D
390k
R4
G
N
D
HT
6
4
0
U1
24
V
CC
23
D
0
22
A
9
21
A8
20
A7
1
9
A
6
1
8
A
5
17
A4
1
6
A
3
1
5
A2
14
A1
1
3
A
0
12
G
N
D
11
OSC1
1
0
OSC2
9
TE
8
D
OUT
7
D7
6
D
6
5
D
5
4
D4
3
D
3
2
D2
1
D1
V
CC
V
CC
G
N
D
DATA IN
G
N
D
IAD
J/
V
CC
RF
OUT
G
N
D
VC
C
PDN
TXM
-
XXX
-
LR
G
N
D
G
N
D
G
N
D
R1
S
et For F
CC
Com
p
lianc
e
Page 6 Page 7Page 7
Figure 7: Schematic Diagram
RECEIVERS
There are four options for receivers within the Linx
product line. The first option is to use one of the OEM
Function Modules, such as the Relay Module or the AC
Wall Module. These items are also pre-certified and
can be immediately included in a product.
The other options are to use one of the Linx receiver
modules. The signal sent by the Keyfob transmitter can
be received by the LC Series receiver module or, for
longer range, the LR Series receiver module. These
modules can be connected to the Holtek HT658
decoder to decode the signal or a custom
microcontroller can be programmed to decode it and
take specific action.
The KH Series offers a slightly simpler solution by
combining the LC Series receiver and the HT658
decoder in a single package.
The basic operation for the system is that when a
button is pressed on the transmitter, a corresponding
pin on the decoder will go high (as long as the
addresses match). This can then be connected to
whatever circuitry is required by the application
Application Note AN00300 discusses in detail how to
set the addresses on all of the units. Data guides for all
of the receivers, the HT640 encoder, and the HT658
decoder can be found on the Linx Technologies web
site, www.linxtechnologies.com.
TYPICAL APPLICATIONS
The outstanding sensitivity of the LR
Series receiver offers the best range
when used with the keyfob
transmitter. When using the LR
Series receiver, the Holtek HT658
decoder chip should be used to
decode the received signal. This
decoder has ten address lines that
must match the keyfob address
lines. A DIP switch is commonly
used to set these, but they can also
be hardwired. If the address lines
match, when a button on the keyfob
is pressed a corresponding data line
on the decoder (D0-D4) will go high.
These data lines can then be
connected to external circuitry to
perform whatever function is
required by the application.
F
C
TN-RLY4-xx
x
F
C
TN-WALL-xx
x
RXM-xxx-L
C
-
S
RXM
-
xxx
-
LR
RXD
-
xxx
-
KH
G
N
D
R1
390k
G
N
D
G
N
D
V
CC
V
CC
D1
1
D2
2
D
3
3
D4
4
D
5
5
D
6
6
D7
7
VT
8
DIN
9
OSC1
1
0
OSC2
11
G
N
D
12
A
0
1
3
A
1
14
A
2
1
5
A
3
1
6
A4
17
A
5
1
8
A
6
1
9
A7
2
0
A
8
21
A
9
22
D
0
2
3
V
CC
24
HT
658
N
C
1
N
C
2
N
C
3
G
N
D
4
V
CC
5
PDN
6
R
SSI
7
DATA
8
N
C
9
N
C
1
0
N
C
11
N
C
12
N
C
1
3
N
C
14
G
N
D
1
5
ANT
1
6
RXM-XXX-LR-
S
G
N
D
Figure 6: LR Receiver and HT658 Schematic
LINX TECHNOLOGIES, INC.
575 S.E. ASHLEY PLACE
GRANTS PASS, OR 97526
PHONE: (541) 471-6256
FAX: (541) 471-6251
www.linxtechnologies.com
U.S. CORPORATE HEADQUARTERS
Linx Technologies is continually striving to improve the quality and function of its products; for
this reason, we reserve the right to make changes without notice. The information contained in
this Data Sheet 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. Linx
Technologies makes no guarantee, warranty, or representation regarding the suitability or
legality of any product for use in a specific application. None of these devices is intended for
use in applications of a critical nature where the safety of life or property is at risk. The user
assumes full liability for the use of product in such applications. 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. Some devices described in this publication are patented. Under no circumstances shall
any user be conveyed any license or right to the use or ownership of these patents.
Disclaimer
WIRELESS MADE SIMPLE
© 2005 by Linx Technologies, Inc. The stylized
Linx logo, Linx, and “Wireless Made Simple”
are the trademarks of Linx Technologies, Inc.
Printed in U.S.A.