Patent ID: 6759951
Filing Date: 2004-07-06
Classification: B61L

Abstract:
A railroad distributed power communication method for wireless transceiver units at spaced locations along a train, with the train having a lead transceiver unit transmitting commands, remote transceiver units spaced from the lead and for which direct communication with the lead unit may be uncertain, and at least one intermediate transceiver unit located between the lead unit and at least one remote unit, the intermediate unit constituting a repeater for repeating messages between the lead unit and at least one of the remote units, the method verifying that a remote unit under the control of the lead unit is following a set of command functions broadcast by the lead unit in a command message, the method comprising:determining whether the lead unit has received a status reply message from the remote unit, the status reply message transmitted in response to the remote unit's receipt of the command message and including data indicative of at least one operational state of the remote unit; transmitting a help command message from the lead unit to the repeater in the event the lead unit has not received the status reply message from the remote unit; repeating the help command message from the repeater to the remote unit; transmitting a help reply message from the remote unit to the repeater in response to the remote unit's receipt of the repeated help command message; repeating the help reply message from the repeater to the lead unit, the help reply message including data indicative of at least one operational state of the remote unit; and receiving the help reply message at the lead unit thereby verifying that the remote unit is following the set of command functions.