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.
