MEGACODE SERIES DIGITAL TRANSMITTERS
MDT, MDT-2 MDT-4
The MegaCode series of digital transmitters are wireless radio controls
designed for use with automatic garage door and gate openers. The MegaCode radio
format provides unparalleled security. The system can be programmed to more than
a million different codes.
MegaCode transmitters and receivers do not contain a typical "coding switch"
as in Linearís standard digital receivers. Each transmitter is pre-set at the
factory to a unique code. Receiving a signal from the transmitter(s) that are
going to be used with it programs the receiver. This stores the transmitterís
code in the receiverís memory. The receiver will retain its memory even without
power. The receiver will activate only from these "memorized" transmitters.
Please refer to the receiverís instructions for maximum transmitter capability.
The transmitters are powered from two type 2032 lithium "button-cell"
batteries. When the batteries get low, the bright red Led light on the
transmitter will start to dim as the unit is activated. When the red LED no
longer lights when the transmitter is activated, the batteries should be
MDT Ė Single-channel transmitter with a button on the front and the top
(both buttons perform the same function.
MDT-2 Ė Three channel transmitter with two buttons on the from and one
button on the top (each button performs
a separate function).
MDT-4 Ė Five channel transmitter with four buttons on the front and one
button on the top (each button performs
a separate function)
************* WARNING *************
Door can cause serious injury or death.
DO NOT install transmitter unless the door
operatorís safety reverse works as required by the door operatorís
Wall control must be mounted in sight of
door, at least 5 feet above floor and clear of moving door parts.
Keep people clear of opening while
door is moving.
DO NOT allow children to play with the
transmitter or door operator.
If safety reverse does not work properly:
Close door then disconnect operator
using the manual release handle.
DO NOT use transmitter or door
Refer to Door and Door Operators Ownerís
Manuals before attempting any repairs.
Electrical Shock can cause serious injury or death.
Power cord must be unplugged before
attaching any wires,
Be sure wire ends do not touch each
other or other terminals.
If you have questions or if you need a manual, contact the distributor or
manufacturer of the operator.
# 1 LOCATING THE PROGRAM BUTTON
MDR/MDRNR/MDR2 Program button and Led
Location. Locate the program button and LED on the side of the receiver case.
MDRM/MDRM2 Program button and LED Location. Locate the program button and
LED on the back of the receiver case.
# 2 PROGRAM RECEIVER
Momentarily press the receiverís program button (channel one or two). The red
programming LED will light if thereís room in the receiverís memory. A
transmitter must be entered while the LED is on. Press the desired
transmitter button. The LED will flicker indicating that the receiver has
accepted the transmitter.
NOTE: Be sure to press the receiver program button for less than 2 seconds.
WARNING: Door operator will not activate when the receiver is being
programmed from the transmitter, but the door operator will activate the next
time the transmitter is activated after programming.
NOTE: The programming LED also monitors radio signals entering the receiver.
It is common to see an occasional blink from the LED. The LED will also light
when any transmitter tuned to the receiverís frequency (programmed into the
receiver or not) is activated.
# 3 ADD ADDITIONAL TRANSMITTERS
Repeat the steps above for each transmitter used with the receiver. Be sure
to press the receiverís program button each time a new transmitter or a
different transmitter button on a multi-button transmitter is pressed. If
the LED doesnít come on when the receiverís program button is pressed, the
receiverís memory is full. Use the erase function to remove transmitters from
the receiverís memory. (Refer to # 6 Erasing Receiver Memory).
#4 REVIEW MEMORY
Press and hold the receiverís program button (channel one or two) until the
LED begins to flash or flashes. The number of flashes equals the number of
transmitters programmed into the channel of the receiver.
NOTE: Donít hold down the programming button longer than 5 seconds, the
receiverís memory for that channel will be erased.
#5 TEST RECEIVER
Be sure door area is clear. Activate each transmitter. The receiver relay
should click, (relay output models only) and the operator should activate.
Wait 2 seconds between each activation.
#6 ERASING RECEIVER MEMORY
Transmitters may be erased for the receiverís memory by pressing and holding
the receiverís program button (channel one or two) for 5 seconds or more. After
the Led blinks (count of transmitters) it will blink one more time for channel
one and twice for channel 2 as the receiverís memory for that channel is erased.
All transmitters for each receiver channel are erased at the same time.
#7 CHANGING THE BATTERY
OPEN BATTERY COMPARTMENT. To access the transmitterís batteries remove the
battery access screw on the back of the unit. Flip the unit over so that the
front is facing you. Use a small screwdriver to open the battery compartment.
REPLACING TRANSMITTER BATTERIES. Replace the two batteries with two type 2032
lithium batteries or equivalent. The batteries stack on top of each other with
the (+) sides facing the front of the transmitter. Replace with new batteries
then close the battery compartment, replace battery screw and test transmitter.
VISOR CLIP REMOVAL. The visor clip can be removed by removing the three
screws on the back of the remote. Slide the clip off the retaining plate and
reattach the plate to the transmitter.
NOTE: The same transmitter (or the same transmitter button on multi-button
transmitters) cannot be programmed into both receiver channels 1 and 2.
NOTE: If the receiverís LED lashes continuously when a transmitter isnít
being activated, the receiver is too close to an electrical noise source. Move
the receiver away from the noise source or call technical services for
Linear radio controls provide a reliable communications link and fill an
important need in portable wireless signaling. However, there are some
limitations which must be observed.
For U.S. installations only. The radios are required to comply with FCC Rules
and Regulations as Part 15 devices. As such they have limited transmitter power
and therefore limited range.
A receiver cannot respond to more than one transmitter signal at a time and
may be blocked by radio signals that occur on or near their operating
frequencies, regardless of code settings.
Changes or modifications in the device may void FCC compliance.
Infrequently used radio links should be tested regularly to protect against
unidentified interference or fault.
A general knowledge of radio and the vagaries should be gained prior to
acting as a wholesale distributor or dealer, and these facts should be
communicated to the ultimate user.