CMD-KEYX-XXX
OEM KEYFOB TRANSMITTER DATA GUIDE
DESCRIPTION
The Linx CMD-KEYX-XXX Remote
Command keyfob is ideal for general-
purpose remote control and command
applications. The unit has been pre-
certified for FCC Part 15 compliance
which reduces costs and time to
product introduction. Available in 315,
418 or 433.92 MHz (418MHz standard),
this stylish and compact remote is
capable of 100+ ft. transmission range.
The unit can be configured with 1-5
buttons and the keypad and labeling
can be customized to meet specific
customer requirements. Selectable
addressing provides security and
allows for 2
10
distinct transmitter-
receiver relationships. The trans-
mission can be decoded using a
matching Linx function module, a KH
series receiver/decoder module or a
Linx LC series receiver paired with a
decoder IC or microcontroller. The unit
operates from a single 3-volt lithium
cell.
0.99"
(25.4)
S4
S1 S5 S3
S2
2.24"
(57.4)
1.35"
(34.6)
0.45"
(11.5)
Physical Dimensions
OEM Configurations
APPLICATIONS INCLUDE:
s
Remote Control / Command
s
Keyless Entry
s
Garage / Gate Openers
s
Lighting Control
s
Security / Call Systems
s
Home / Industrial Automation
Revised 6/11/01
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.
ORDERING INFORMATION
PART #
DESCRIPTION
CMD-KEYX-315
315 MHz Keyfob Transmitter
CMD-KEYX-418* 418 MHz Keyfob Transmitter
CMD-KEYX-433
433 MHz Keyfob Transmitter
X= # of buttons - insert 1-5
* = Standard Frequency
PERFORMANCE DATA– CMD-KEYX-XXX
ABOUT THESE MEASUREMENTS
The performance parameters listed below are based on module operation at 25°C
from a 3Vdc supply unless otherwise noted.
RF-Parameters
CMD-KEYX-315
Frequency of Carrier
Harmonic Emissions
Designation
F
C
P
H
Min.
314.925
–
Typical
315
–
Max.
315.075
-40
Units
MHz
dBc
Notes
–
–
RF-Parameters
CMD-KEYX-418
Frequency of Carrier
Harmonic Emissions
Designation
F
C
P
H
Min.
417.925
–
Typical
418
–
Max.
418.075
-40
Units
MHz
dBc
Notes
–
–
RF-Parameters
CMD-KEYX-433
Frequency of Carrier
Harmonic Emissions
Designation
F
C
P
H
Min.
433.845
–
Typical
433.92
–
Max.
433.995
-45
Units
MHz
dBc
Notes
–
–
Electrical Parameters
CMD-KEYX- 315,418, 433MHz
Operating Voltage Range
Current Average
Current In Sleep
Output Power
TX Data length
Average Data Duty Cycle
Encoder Oscillator
Operating Temperature
Designation
V
CC
I
CA
I
SLP
P
O
FE
NC
Min.
Typical
Max.
2.7
–
3.2
–
1.7
–
–
0
-
PART 15.231 Compliant
26bits 3x
50%
70
-30°C
to
+70°C
Units
Vdc
mA
µA
Notes
–
1
2
KHz
Notes:
1. Current draw with 50% mark/space ratio.
2. Current draw in standby
THEORY OF OPERATION
The CMD-KEYX-XXX Keyfob Command Unit combines a high-performance SAW-
(Surface Acoustic Wave) based transmitter with an on-board encoder. The keyfob
can transmit the status of 1 to 5 buttons along with the state of ten address lines
for security and creation of unique transmitter/receiver relationships. The product’s
operation is straightforward. When a button is pressed, power is applied to the
internal circuitry and the encoder IC is enabled. The encoder then detects the logic
states of the address traces and button data lines. These states are then formatted
into a 3-word transmission cycle which 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. The transmitted signal may be received by any
Linx KH or LC receiver or pre-made function module of the same frequency. Once
data is received it is decoded using a decoder IC or custom microcontroller. The
transmitted address bits are checked against the address settings of the receiving
device. If a match is confirmed, the decoder’s output(s) are set to replicate the
transmitter’s button status.
Page 2
SETTING THE TRANSMITTER ADDRESS
The keyfob allows the selection of one of
1024 unique addresses. All keyfobs from
the factory are supplied set to the same
address. To avoid ID contention with
other units in the vicinity or to create
unique relationships it may be helpful to
change the address settings. This may be
accomplished by cutting the appropriate
jumper trace(s) with a sharp object such
as an X-acto knife as shown. The traces
are accessed by removing the rear cover
as for battery replacement.
9 876543210
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 frequency can occupy airspace without contention
at any given time.
BATTERY REPLACEMENT
The remote unit utilizes a CR-2032 Button Lithium Cell.
In normal use it will provide 1-2 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 the battery out from
beneath the retainer. Replace with the same type of cell
while observing the polarity shown.
+
Battery
COMPLIANCE REQUIREMENTS
The CMD-KEYX-XXX 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-KEYX-XXX Remote Command Unit 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
statement on page 7 in the end product’s instruction manual or insert card.
Page 3
Schematic Diagram
VCC
S1
U1
TOUCHPAD
S2
HT-640
1
2
3
4
5
6
7
8
9
10
11
12
D1
D2
D3
D4
D5
D6
D7
DOUT
TE
OSC2
OSC1
GND
HT-640
GND
50
Ω
RF OUT
(Ant.)
Keyed Output
TOUCHPAD
S3
R4
TOUCHPAD
S4
390K
TOUCHPAD
S5
Output Isolation
& Filter
TOUCHPAD
Page 4
VCC
HT-640
D1
D2
D3
D4
D5
D6
D7
DOUT
TE
OSC2
OSC1
GND
HT-640
GND
SAW
Oscillator
VCC
D0
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
24
23
22
21
20
19
18
17
16
15
14
13
CUT TRACE FOR
ADDRESS SELECT
VCC
B1
BATT
GND
Vcc
S4
S1 S5 S3
S2
ation
RF Amplifier
Page 5
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