| Word | Description |
|---|---|
| Macro | Multiple DCC Commands generated by some systems to perform a task such as Programming or setting a Route for turnouts. The macro is activated by a throttle or other device such as a push button input on a stationary decoder. |
| Manual Block System | Prototype train control system where by trains run from block station to block station. Trains require explicit authority to enter each block. Also used as the backstop method if an automated signaling system fails. |
| Master/Slave | A system architecture where a central controller manages communications among attached devices. Master/slave usually uses polled communications. |
| Max voltage (Vmax) | CV05 specifies the exact voltage to apply to the motor at speed step 28 in a 28 step system and step 14 in a 14 step system. Setting CV05 limits the top speed of the loco. |
| Mid-Point Voltage | CV 06 specifies the exact voltage to apply to the motor at speed step 15 in a 28 step system and step 7 in a 14 speed step system. This allows you to make a quick adjustment to the motor voltage/speed curve without setting up a loadable speed table. |
| Momentum | Expresses an object's tendency to keep moving at its current speed and direction. |
| Motorola Trinary Format | A digital command control format used by Marklin AC digital HO and Marklin Maxi decoders. This format is the largest format used in Germany and is not compatible with DCC. Some command stations like Digitrax DCS100 and Uhlenbrock can output both Marklin Motorola and DCC formats simultaneously. |
| MU | Multiple unit operations. The action of linking more than one power unit together to be controlled by a single address. Also called Multiple Unit Operation, MU'ing, Multiple Unit Lash Ups, etc. |