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DESCRIPTION
The Linx CMD-HHTX-*** Remote Command
Unit is ideal for general-purpose remote control
and command applications. As a part of our
Holtek encoder-based OEM family, it has been
pre-certified for FCC Part-15 compliance, which
reduces costs and time to product introduction.
Available in 315, 418 (standard) or 433.92MHz,
this handheld remote has a transmission range
of up to 1,000 feet when combined with the LR
Series receiver. The transmitter can be
configured with 1 to 8 buttons and the keypad
and labeling can be modified to meet specific
OEM customer requirements. Selectable
addressing provides security and allows the
creation of up to 256 distinct transmitterreceiver relationships. The transmission can be
decoded using a matching Linx function
module, a Linx KH Series receiver / decoder or
Linx LR or LT Series receiver paired with a
decoder IC or microcontroller. The unit operates
from a single 3V CR2032 lithium button cell.
FEATURES
FCC pre-certified
1 to 8 buttons
Small package
Customizable keypad
APPLICATIONS INCLUDE
General Remote Control
Keyless Entry
Garage / Gate Openers
Lighting Control
Call Systems
Home / Industrial Automation
OEM HANDHELD TRANSMITTER DATA GUIDE
Revised 1/28/08
Figure 1: Package Dimensions
WIRELESS MADE SIMPLE
®
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.
PART # DESCRIPTION
CMD-HHTX-***-xxx OEM Handheld Transmitter
EVAL-***-HHTX HHTX Evaluation Kit
*** = 315, 418 (Standard), 433.92 MHz
ORDERING INFORMATION
3.35"
1.81"
2
1
3
4
D
C
A
B
FASCO
0.62"
O
ON
ON
O
FF
ON
O
FF
ON
FF
Spa
Lights
Pool
0.17"
O
N
O
N
O
N
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THEORY OF OPERATION
The CMD-HHTX-*** OEM Handheld transmitter combines the LC Series
transmitter and Splatch planar antenna with an on-board Holtek HT640 encoder
IC to form a simple, yet highly reliable, RF remote-control transmitter. The LR
Series transmitter is a low-cost, SAW-based ASK / OOK transmitter.
When a button is pressed on the transmitter, power is applied to the internal
circuitry and the encoder IC is enabled. The encoder detects the logic states of
the address lines and button data lines. These states are formatted into a threeword 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
LR, KH2, LT, 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 transmitter is combined with an LR Series receiver and the HT658 decoder
chip, 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
Parameter Designation Min. Typical Max. Units Notes
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
CMD-HHTX-315 – 315 – MHz –
CMD-HHTX-418 – 418 – MHz –
CMD-HHTX-433 – 433.92 – MHz –
Center Frequency Accuracy – -50 – +50 kHz –
ENVIRONMENTAL
Operating Temperature Range – -30 – +70 °C 1
SETTING THE TRANSMITTER ADDRESS
The OEM Handheld transmitter allows
the selection of one of 256 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 using
internal DIP switches as shown. The
switches are accessed by removing the
rear cover as for battery replacement.
If the switch is on, 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 AN-00300
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,
www.linxtechnologies.com.
CMD-HHTX BUTTON ASSIGNMENTS
This diagram illustrates the relationship between the button locations and
encoder data lines.
Figure 3: CMD-HHTX-*** Button Assignments
Figure 2: DIP Switch Assignments
ON OFF
A0 = 8
A1 = 7
A2 = 6
A3 = 5
A4 = 4
A5 = 3
A6 = 2
A7 = 1
D7 D6
D5 D4
D3 D2
D1 D0
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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-HHTX-*** has been pre-certified by Linx for FCC Part 15 compliance
when used with an appropriate function module in keeping with the applications
allowed under section 15.231.
LABELING / INSTRUCTION REQUIREMENTS
The CMD-HHTX-*** Handheld transmitter has already been labeled in
accordance with FCC 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.
Figure 5: CMD-HHTX-*** 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 CR2032 lithium
button cell. In normal use, it will provide 1 to 2 years
of operation. To replace the battery, remove the
screw in the middle of the back cover. Once the unit
is open, remove the battery by depressing the
release finger on the battery holder as shown.
Replace it with the same type of battery while
observing the polarity shown in the adjacent figure.
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.
ASSEMBLY DIAGRAM
Battery Release
+
Figure 4: Battery Access
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Figure 7: CMD-HHTX-*** Schematic
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 OEM Handheld
transmitter can be received by the LR Series receiver
module or the LT Series transcever 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 KH2 Series offers a slightly simpler solution by
combining the LR Series receiver and the HT658
decoder in a single package.
When a button is pressed on the transmitter, a
corresponding line 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 AN-00300 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
website, www.linxtechnologies.com.
TYPICAL APPLICATIONS
The outstanding sensitivity of the
LR Series receiver offers the best
range when used with the
Handheld 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 transmitter
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 transmitter is pressed a
corresponding data line on the
decoder (D0-D7) will go high.
These data lines can then be
connected to external circuitry to
perform whatever function is
required by the application.
GND
390k
GND
GND
CC
CC
3
3
5
5
6
6
8
9
OSC1
0
OSC2
GNDA0
3
5
3
6
5
8
6
9
0
8
9
0
3
CC
658
C
C
C
3
GND
CC
5
6
SSI
8
C
9
C
0
CNC
C
3
C
GND
516
GND
Figure 6: LR Receiver and HT658 Schematic
V
VCC
24
VCC
16151413121110
S1
1234567
9
8
13A114A215A316A417A518A619A720A821A922D023
A0
GND
ADDRESS
VCC
8
7
GND
ANT1
6
VCC
1
5
GND
GND2GND3GND4GND5GND
RFIN
RFOUT
SPLATCH ANTENNA
6
GND
GND
D1
U1
1D22D33D44D55D66D77
DOUT8TE9OSC1
OSC211GND
10
HT-640
12
DATAIN2GND3IADJ/GND
GND
TX1
1
4
TXM-xxx-LC
GND
390K
R1
R2
100K
23
DPAK-X2
U3
4
U2
N
N
N
V
R
-
D
D
D
1
HT
1
N
1
N
N
1
N
N
V
V
2
D
A
A
2
1
A
1
A
1
A
1
A
A
1
VCC
1
SW22SW33SW44SW55SW66SW77SW8
SW1
8
4
9
COM
23
DPAK-X2
U4
1
4
VCC
23
DPAK-X2
U5
1
4
B1
DPAK-X2
CR2032
1
23
1
GND
GND
SM1
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LINX TECHNOLOGIES, INC.
159 ORT LANE
MERLIN, OR 97532
PHONE: (541) 471-6256
FAX: (541) 471-6251
www.linxtechnologies.com
U.S. CORPORATE HEADQUARTERS
WIRELESS MADE SIMPLE
®
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
Overview 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 the customer's responsibility
to verify the suitability of the part for the intended application. NO LINX PRODUCT IS INTENDED FOR USE
IN ANY APPLICATION WHERE THE SAFETY OF LIFE OR PROPERTY IS AT RISK.
Linx Technologies DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. IN NO EVENT SHALL LINX TECHNOLOGIES BE LIABLE FOR ANY OF
CUSTOMER'S INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY FROM ANY DEFECTIVE
OR NON-CONFORMING PRODUCTS OR FOR ANY OTHER BREACH OF CONTRACT BY LINX
TECHNOLOGIES. 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. The Customer will indemnify, defend, protect, and
hold harmless Linx Technologies and its officers, employees, subsidiaries, affiliates, distributors, and
representatives from and against all claims, damages, actions, suits, proceedings, demands, assessments,
adjustments, costs, and expenses incurred by Linx Technologies as a result of or arising from any Products
sold by Linx Technologies to Customer. 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. Under no circumstances shall
any user be conveyed any license or right to the use or ownership of such items.
Disclaimer
© 2008 by Linx Technologies, Inc. The stylized Linx logo,
Linx, “Wireless Made Simple”, CipherLinx, and the stylized
CL logo are the trademarks of Linx Technologies, Inc.
Printed in U.S.A.
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