Terminal Loops In Digital Operation; Glossary - Roco multiMAUS Manuel

Terminal Loops in Digital Operation

Every model railway enthusiast knows the problem of terminal loops from his / her conventional system. In digital
operation too, the left-hand rail profile meets the right-hand rail profile after a terminal loop and would cause a
short circuit without the appropriate wiring.
The ROCO 10769 terminal loop module solves the problems of a terminal loop in digital operation. Isolate the
terminal loop with both poles on both sides by disconnecting the terminal loop completely from the rest of the
system, using either insulated connectors or by sawing the rail profiles (see fig. 5 on page 64). It is imperative that
the isolated section of track within the terminal loop is longer than the longest train which is going to travel through
the terminal loop. The power supply to the terminal loop is connected to the output of the terminal loop module
which provides the power supply for the terminal loop. The module itself is connected either to a track outside the
terminal loop or directly to the amplifier.
The terminal loop module functions as follows: A train enters the terminal loop – the direction is not important –
and the polarity of the tracks before and within the terminal loop is not identical. There is then a short circuit within
the module which the module immediately detects. The module then reverses the polarity in the terminal loop
before the short circuit detection function of the amplifier detects anything or the train slows down. The terminal
loop polarity is then corrected for the entry of the train. The reverse of polarity in the terminal loop does of course
render the polarity incorrect for the train's exit from the loop. This procedure or reversing the polarity is therefore
repeated when the train exits. Since in digital operation the polarity of the tracks do not determine the direction
of travel of the train; the train can pass through the terminal loop without stopping or without your intervention.
In order for the terminal module to detect incorrect polarity in time, you have to set its sensitivity using the poten-
tiometer visible on the side. See the terminal loop module's instructions for use.

Glossary

� Decoder
In order to make the digital control signals of the multiMAUS understandable to "conventional" technology, you
require a "translator" – the decoder. It does not replace any of the components in the analogue direct current loco-
motive but is a necessary addition and must also be given a place in the locomotive housing. For alternating current
locomotives on the other hand, the change-over module or relay is replaced by the decoder, not in DCC format but
of course Motorola format.
� CVs
All values which affect the behaviour of the locomotive decoder – and ultimately the behaviour of the locomotive
– are stored in what are referred to as CVs. CV is the abbreviation for configuration variables. The multiMAUS is
compatible with the NMRA / DCC standard and can therefore read and write these variables.
ROCO amplifiers 10761 and 10764 and booster 10762 and 10765 cannot be used to read the CVs from a decoder!
The values shown are only fictitious suggested values.
CVs range from "0" to "255". This shows that reprogramming requires experience, as incorrectly set CVs may have
an adverse effect on the performance of the decoder.
� Speed steps
On a conventional model railway a regulating transformer is used to control locomotives. The transformer emits
voltage values to control the locomotive motor between 0 volts and the maximum voltage (typically between 12 and
16 volts) via the controller.
In a digital system on the other hand, the track always carries a fixed constant voltage. The motor is controlled
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