Abstract: The communication system has a plurality of subscribers connected through respective interface circuits to a ring feeder for the common transmission of digital source data and control data. The source data and control data are transmitted in a format which prescribes a pulsed sequence of individual bit groups of equal length. The bit groups are subdivided into component bit groups each forming a data channel. At least one date channel is provided for control data which are transmitted in data packets with a destination address. Furthermore, the interface circuit of each subscriber contains an address decoder. The communication system is simplified, and changes to the system are made easier in that at least one subscriber has a special address by means of which a received data packet is fed directly to an instruction decoder inside the interface circuit, which decodes to the bit base an instruction code contained in the data packet. The interface circuit, i.e.

Abstract: A method for entering and leaving a power-saving operation of a subscriber in an annular communication network includes transmitting data in the communication network in a format that prescribes a pulsed sequence of individual bit groups of identical length in which specific bit positions are reserved for a preamble which is decoded in a receive circuit of each subscriber. During a power-saving operation of a subscriber, at least part of the subscriber which contains the receive circuit remains turned on, and at least one special preamble code is provided, upon the reception of which a part of the subscriber turned off during the power-saving operation is turned on again.

Abstract: A method for the common transmission of digital source data and control data between data sources and data sinks. The data sources and data sinks are subscribers in a communication network with a ring structure. The source data and control data are transmitted in a format which prescribes a pulsed sequence of individual bit groups of identical length. Specific bit positions in each of the bit groups are reserved for source data and control data. The transmission is in a continuous data stream synchronous with a clock signal. An arbitrarily large contiguous region of the bit positions can be reserved for the source data within a bit group for data which are transmitted in data packets. Each of the data packets has a start with a subscriber address and a defined length.

Abstract: A method for compensating for propagation time delays in a communication network includes connecting each of a plurality of subscribers to a ring feeder for a common transmission of digital source data and control data in a data stream synchronous with a clock signal. The source and control data are transmitted in a format prescribing a pulsed sequence of individual bit groups of identical length containing component bit groups each forming a data channel for source data or control data. At least two subscribers, which are connected at different locations to the ring feeder, receive source data that are transmitted by one of the subscribers on different data channels and are correlated with one another. Specific bit positions are reserved in each bit group for a numerical value relayed from subscriber to subscriber. The numerical value is always set by one of the subscribers to a fixed initial value and incremented by each following subscriber along the ring feeder.