Method and apparatus for controlling electro-pneumatic braking on a train

An apparatus for controlling electro-pneumatic braking on a train of ECP equipped railcars using a pneumatic brake valve located in a cab of a locomotive of the train, said locomotive and ECP equipped railcars interconnected by a brake pipe and a brake control signaling system, said apparatus comprising:

• a. an operator control portion connected to said brake valve and operable to cause a pressure change representative of a pneumatic brake command;
• b. a relay valve in communication with at least said brake valve and said brake pipe, said relay valve conventionally causing pressure in said brake pipe to mirror said pressure change;
• c. an interface unit in communication with at least said relay valve, said interface unit controllable to isolate said relay valve from said pressure change such that said relay valve does not mirror said pressure change in said brake pipe;
• d. a pressure sensor communicating with said brake valve at least when said interface unit isolates said relay valve, said pressure sensor producing a signal corresponding to said pressure change;
• e. an ECP controller receiving said signal and controlling braking on said railcars based upon said pressure change via said brake control signaling system;
• f. an equalizing reservoir in communication with said brake valve, said relay valve, and said pressure sensor, said pressure change caused in said equalizing reservoir by said brake valve;
• g. said interface unit interposed between said equalizing reservoir and said relay valve for isolating said relay valve from said pressure change caused in said equalizing reservoir;
• and
• h. said interface unit interposed between said equalizing reservoir and said pressure sensor, said interface unit connecting said equalizing reservoir with said pressure sensor while isolating said relay valve portion from said equalizing reservoir and connecting said relay valve to a reference pressure source.