Device for the signal-technical secure control and monitoring of electrical loads

Apparatus for remotely controlling and monitoring the operational states of a plurality of spatially-proximate loads, comprising:

• a control station including a command transmitter operable to cyclically transmit predetermined commands representing desired operating states of the loads;
• a command receiver for receiving the commands;
• switching means connected between said command receiver and the loads and operable in response to the received commands to condition the loads into the desired operating states;
• monitoring means connected to said loads and operable in response to the actual operating states thereof to produce a corresponding message;
• a message transmitter for transmitting the messages to said control station;
• a message receiver in said control station for receiving the command messages;
• comparison means in said control station connected to said command transmitter and said message receiver and operable to produce an alarm signal in response to inequality of content between a command and its reply message after the prescribed cycle interval;
• control means in said control station connected to said comparison means and to said command transmitter for causing said command transmitter to transmit logic control commands, said logic control commands being formed by cyclically changing reversely-transmitted commands indicating change-overs from one tranmission to another;
• and
• logic means connected to said command receiver and to the loads, normally conditioned to permit the cyclic predetermined operation of the loads and responsive to the logic control command to condition the loads into a special operating state in the event of the changing logic control commands not occurring over a predetermined cycle time, such non-occurrence being able to be produced by the control means too in response to predetermined disturbances in operation of the control and monitoring means.