The lead locomotive in an m.u. consist must first be selected on the other side of the locomotive controller in order to set up a double or m.u. locomotive consist on one side of the locomotive controller. This locomotive can be added to the consist with the button  . 
After that you can select the second locomotive and add it to the consist as described above. Make sure that the last direction of travel set on locomotives is the same as the preferred direction of travel for the consist before adding them to the consist.

Under "Name" a name of your choice should be assigned to the consist. The consist is shown with its name in the locomotive list. When the consist is called up, the image of the lead locomotive will be shown.

The button  can be used to remove any locomotive from the consist.

In order to avoid damage to the locomotives, a consist should consist only of locomotives similar to one another with similar settings for maximum speed (VMax) and acceleration and braking delay.

Note: When a consist is being run on one locomotive controller, one of the locomotives in that consist can be called up on the second locomotive controller. The latter controller will then always show the corresponding status for the locomotive called up. However, if the speed for that locomotive is changed, it will change the actual speed of that locomotive in the consist. This allows you to run a locomotive away from a consist without it being deleted from the consist.