초록 ▼

A powered communications link between a central controller and a remote substation along a conductor that includes a movable or intermittent contact interacting therebetween includes a power supply located at the central controller for supplying electrical power over the conductor to the remote subs

A powered communications link between a central controller and a remote substation along a conductor that includes a movable or intermittent contact interacting therebetween includes a power supply located at the central controller for supplying electrical power over the conductor to the remote substation and an electrical power storage device at the remote substation for storing the power supplied over the conductor. Data and power are multiplexed over the conductor by the central controller which periodically stops the application of power to the conductors to permit a transmitter at the remote substation to send data to the central controller. A switch at the remote substation connects the power storage device to the conductor when power is being sent and disconnects it at all other times.

대표청구항 ▼

A powered communication link between a central controller and a remote substation comprising a single conductor having a movable or intermittent contact interacting therebetween, wherein said remote substation is powered by pulses of electrical power supplied by the central controller over the condu

A powered communication link between a central controller and a remote substation comprising a single conductor having a movable or intermittent contact interacting therebetween, wherein said remote substation is powered by pulses of electrical power supplied by the central controller over the conductor, said pulses alternating with data messages transmitted between said central controller and said remote substation over said conductor, and including auxiliary signalling means for generating an alarm signal actuated by a switch at the remote substation normally providing said alarm signal to the central controller over the conductor as part of a data message, and failsafe relay means at the remote substation triggered by a loss of electrical power for connecting said auxiliary signalling means directly to said conductor in the event of a loss of electrical power at said remote substation to generate said alarm signal independently of said data message.