The foot pedal is a normally open switch which can be placed at the co-pilote to reset the trip distance. Also any other Normally open momentary switch can be used for this purpose. It is also possible to have more than 1 switch in parallel to relieve your feet at certain stages.
The footpedal is usually used in cars where it is not possible to install a foot switch while a foot switch is easier to install firmly to a foot rest and does not take up a lot of room on your foot restand is still easy to hit.
For the foot pedal you only have to connect 1 wire to the tripmaster. The other wire goes to the ground of your car (can be done in the tripmaster of course).
All external switches in our system are always switched to the ground: This only gives the need for 1 wire and if the wire is damaged and comes in contact with your car, you will only get a strange readout but not electrical short circuit will happen..