Mtroniks MRLA User manual

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MRLA Manual Mtroniks Ltd. July 2019
Loco Radio Adaptor (MRLA)
Thank you for purchasing your Mtroniks Loco Radio Adaptor (MRLA), this unit has had the benefit of careful in-
the-field testing and Mtroniks’ extensive experience of radio control equipment.
Dimensions: 95.00 x 55.00 x 30.00mm Weight: 100.0g
Caution
Do not plug a battery into your MRLA. The MRLA takes its power from its connection to the ACI/DCI main unit
and then powers the radio receiver. Connecting an additional power source to the MRLA’s radio channels
could cause damage to it, or to the ACI/DCI unit that it connects to.
This system is not suitable for use with any system servos. Please contact Mtroniks is this is something you
might want to do.
Do not start the system until your transmitter is switched on, with all its channels in the centre position. It is
strongly advised that each radio channel to be used is tested using the MRLA’s Signal Tester mode (see below),
prior to attempting to control a loco.
Safety is crucial, particularly with a potentially very large locomotive model. The loco must be supervised at all
times and fitted with an accessible power isolation switch. When unsupervised, the loco must be left safe and
without the possibility of tampering causing it to become operational.

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MRLA Manual Mtroniks Ltd. July 2019
Description
The MRLA has:
•One multi-way cable which connects to the Mtroniks ACI/DCI main power unit. This carries
communication information between the power unit and the MRLA, also this cable supplies power
from the main ACI/DCI power unit to the MRLA which is then passed on to the radio receiver. This
power level is at 5V DC, suitable for all such pieces of radio equipment. It is important that this power
source is not overloaded (e.g. by connecting servo devices to the radio receiver), this could damage
the main ACI/DCI power unit.
•4 cables which connect to a radio receiver. Correct connection and polarity of Signal, Positive and
Negative are essential; please refer to your radio receiver’s manual. Each of these cables is labelled,
indicating its function: THR=throttle/brake control channel, DIR=direction control channel,
LAT=latching auxiliary functions channel, MOM=momentary action auxiliary functions channel. Each
receiver channel has a matching transmitter control channel. The user should choose transmitter
channels for operation that he feels with comfortable with and connect the MRLA’s cabling to the
appropriate receiver channels. It is essential that the user feels comfortable with, and has a good
knowledge of, the control channels.
•A push button that causes the MRLA to enter “Signal Tester” mode.
•LED indicators giving visibility of the MRLA’s main functions: Operation LED (doubling as Signal Tester
LED), Battery Condition LED, Alert LED.
Operation
Signal Tester Function
This function allows the testing of the radio system. All channels that are going to be used to control the MRLA
should be tested for appropriate behaviour prior to using the MRLA to control a loco.
When in Signal Tester mode, the MRLA will light an LED depending on the condition of the signal that is seen
on its “Throttle” input channel.
Power must be removed from the MRLA to cause it to leave Servo Tester mode.
Signal Tester Procedure
With system powered down and motors disconnected from the ACI/DCI power unit:
1. Plug the MRLA’s THR cable into the channel of the radio receiver that is to be tested. Plug the MRLA’s
multi-way cable into the ACI/DCI power unit.
2. Power up radio transmitter.
3. Power up ACI/DCI power unit WITH the MRLA’s push button pressed. Button must be pressed while
power is applied otherwise, the unit will enter normal running mode, not signal tester mode.
The MRLA will monitor the signal that it sees on its THR channel. The appropriate channel of the radio
transmitter should be then adjusted.

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MRLA Manual Mtroniks Ltd. July 2019
In order for the MRLA to be controllable, all radio channels to be used must conform to the below behaviour;
•When the radio channel is centred, the MRLA’s Signal Tester LED will light constant Amber. As the
channel is moved positively, the LED will begin flashing Green, at the extreme of that movement, the
Green LED will become constant. In the channel’s negative direction, the LED will behave that same
way, but showing Red.
•The radio channel may operate in the opposite direction to described above, if so, it is the user’s
choice as to whether to reverse that operation as detailed in the radio system’s instructions.
•If the LED does not light constant Amber when centred, the channel may need an adjustment, or
‘trim’.
•If the channel does not reach the constant Red/Green state as described above, the channel’s ‘high
point’ adjustment may need altering. This should be detailed in the radio system’s instructions.
It is essential for the above conditions to be met for the MRLA to properly control the ACI/DCI unit.
4. Power-down the system.
5. Repeat the above procedure completely for each channel of the radio system that is to be used.
Power must be removed from the MRLA to cause it to leave Servo Tester mode.
Normal Operation
Once everything is connected properly and the radio system is set up properly, normal operation can
commence.
Switch on your transmitter, with fully charged batteries before activating the main ACI/DCI power unit. It is
best to switch on the transmitter with all its controls centred.
The MRLA starts up in a safety lock-out mode, flashing its Operation LED from Red to Green repeatedly. To
leave this mode and begin normal operation, the transmitter’s Throttle control must go through this
procedure: Centre to full negative, THREE times, then back to centre. A procedure like this is essential to
prevent accidental activation of the loco. Also, when in normal operation, this same procedure is used to put
the MRLA into a safe, de-activated state.
The throttle control when moved positively causes the ACI/DCI to power the motors. When used negatively,
the ACI/DCI will brake the motors.

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MRLA Manual Mtroniks Ltd. July 2019
The MRLA’s Operation LED, when in normal running mode, indicates the direction of travel that the unit is set
for: Green for forward, Red for reverse. Direction of travel is changed by holding the transmitter’s Direction
channel in the appropriate direction for greater than 3 seconds. The Operation LED will then change colour
and it will be necessary to return the Throttle control to centre/brake for a few seconds before the ACI/DCI will
engage the new direction of travel.
Latching auxiliary function control: the transmitter channel that has been chosen for this function will activate
(or deactivate) a latching auxiliary function when moved to one of its extremes. To deactivate this function,
the radio channel must be moved back to centre, then returned to that extreme. At power-up, latching
functions default to Off.
Momentary functions operate when the appropriate radio channel is moved to one of its extremes, when
moved away from its extremes, momentary functions are cancelled.
Wavering
Since safety is crucially important, the MLRA has a function that will cause it to shut down and bring the
Locomotive to a standstill if user intervention is not detected. The MRLA constantly checks the signal it sees
from the receiver and looks for a “wavering” effect. When a user is handling a radio transmitter, naturally his
fingers will cause small changes in the control, the MRLA looks out for this Wavering as evidence that the user
is in control of the model. If the transmitter is left unattended, its signal output will remain static. In this
condition, the MRLA will, after a period sound an audible alarm and flash its Alert LED. If action is not taken,
then, shortly after, the MRLA will go into Safety Interlock Mode. To prevent this happening it is necessary for
the user hold his transmitter and periodically make small changes to the position of the throttle control –this
“Wavering” usually naturally happens as a function of controlling the model, and as this happens, the MRLA’s
internal safety counter will be reset. Usually, the natural movement of the Throttle channel will cancel the
MRLA’s safety alert, however, under some conditions, the user may want to keep his throttle control in a very
constant position, e.g., when performing a long ascent up a gradient, for this reason, the MLRA’s direction
control channel also performs the Wavering function in exactly the same way as the throttle control, a small
movement of this channel, ideally around the centre, Neutral, position will be enough to cancel the Safety
Interlock Mode timer and prevent shutdown.
Once the MRLA has entered shutdown mode, it will set its outputs to bring the locomotive to a halt and then
silence its buzzer. The Alert LED will remain on and the usual start-up procedure will have to be followed to
restart the model.
When in Neutral, or Braking areas, the Dead Man Safety function will take longer to operate, since these
conditions are safer than when the loco is being driven. The shutdown function will though take effect after
this extended period as an essential safety function.
Battery Condition
The MRLA receives battery condition from the main ACI/DCI power unit. A tri-colour LED indicates: Green –
battery good, Amber –battery medium, Red –battery low. Under conditions of high load, like acceleration or
labouring up an incline, it is not unusual for a healthy battery to sometimes dip into the Amber, or Red zones.