Abstract: A method for performing a bus request or collective acknowledgement on a bus system, in a process bus system for serial data transmission, including subscribers of the process bus system, and a bus control device, includes generating a band-limited signal capable of superposition at all of the subscribers, in accordance with a common given principle, transmitting the band-limited signal with the subscribers for performing a bus request or collective acknowledgement, and analyzing the signal with the bus control device, and a device for carrying out the method.

Abstract: A process for exerting control over a remote facility by transmission of control data protected against error due to component breakdown and/or failure as a result of said process, which comprises; creating a message having a plurality of bits in which the states of at least selected ones of the bits determine the presence (or absence) of a particular command; transmitting the message in serial fashion; inverting the message bits after each message transmission so that the bits of the message are transmitted in true and inverted form in an alternating fashion. The message bits are preferably employed to modulate a carrier. A receiver demodulates the carrier and places the message bits representing a particular command across a transformer input winding. The transformer preferably has a saturable magnetic core having a right-angle hysteresis curve characteristic.