If you are using the Motion Encoder Cart (DTS-CART-MEC) on a long 2.2 m track, you will need to adjust the emitter to the 2 m setting. The switch is located directly under the tab used to open the battery compartment.

The IR transmitter on the cart has two power levels available. The default 1 m setting conserves battery power. If the cart is used on a 2.2 m track, set the cart to the higher 2 m power level. If this setting is not used, the receiver will not reliably sense the position of the cart at the far end of the track.